My divorce remains, five years later, the single biggest transformative event in my life so far. I guess that’s the true meaning behind anniversaries: they mark those memorable dates when your entire life changes overnight, a temporal Rubicon delineating the inescapable shift from Before to After.

I’m learning, five years later, that you don’t get over divorce; you just move on. Even after your heart has healed from the initial shock of loss, the divorce itself–the end of almost thirteen years of marriage with someone you assumed you’d spend your entire life with, and the complex emotional aftermath as you disassemble that assumption and build something different with your life and dreams–continues on. You don’t get “over” it in the sense of forgetting it happened or returning to who or what you were “before.” The Biblical definition of “marriage” is “two people become one flesh,” and there’s a more-than-metaphoric sense in which divorce is an amputation. You can resume a normal life after losing a limb: you can learn to walk on one leg, for instance, and you can return to living a full and rich life. But you never really forget that you once had two legs.

My ex has literally moved on since our separation and divorce, remarrying three years ago and moving from place to place in search of a happy life: I wish him and his wife well. The path to divorce is an incremental abandonment of hopes and promises: first you give up hope that you’ll ever be happy in your marriage, then you give up hope that you’ll ever make your partner happy. That latter hope was the last to die, and its passing was, for me, the one I couldn’t ultimately handle. In twelve years of marriage, I had long practice letting my own dreams die, but the thought that I’d ultimately failed my spouse–the realization that I’d never tame his wildly changing moods, never succeed in settling him down into an existence that was, to my eye, stable and content–was the one sacrifice I ultimately couldn’t swallow.

In retrospect, my ex and I defined happiness differently…and to be perfectly honest, I never did learn much less understand his personal definition of the term. For me, happiness is defined (or at least it is indicated) by stability and constancy: if you’re happy with something, you’ll stay with it rather than perpetually looking for something better or simply different. It’s telling, for instance, that I still have the same job, the same apartment, the same hobbies, the same spiritual practice, and the same creative pursuits now as I did when I was married: because I’m happy with those things, I haven’t changed or replaced them.

My ex, on the other hand, was eternally beholden to change, seeing constancy as boredom and boredom as creative death. My ex always wanted to travel, to move, to change jobs, and to embark on new enterprises, and when the novelty of any one of those wore off, he’d seek a new diet, a new hairstyle, or a new piece of musical or recording equipment to console himself with “something different.”

For almost thirteen years, I blamed myself for my then-husband’s volatility, assuming that if he wasn’t happy enough to settle into the mundane boredom I find sustaining, it was because I wasn’t making him happy. Only in retrospect have I come to fully realize that mutability was an essential part of who my ex was (and possibly still is). “Taming” my ex’s addiction to novelty and change wasn’t the kind of thing I or probably anyone could accomplish: perpetual change was an essential part of his character, something I simply didn’t and probably couldn’t understand.

Even without the impetus of an anniversary, I think of my ex-husband every autumn, his favorite time of year: it’s no accident, I think, that he married both me and his second wife in this season of change. My ex was prone to seasonal depression, and autumn offered a spell of brief, bittersweet beauty before another long, emotionally turbulent winter. My ex’s dark moods were like an old girlfriend who arrived in November and made herself at home through March: there really were three of us, at least, in that marriage. In retrospect, I blamed myself, again, for my ex’s light-starved upheavals, somehow thinking that this year, if we did something (anything!) differently, he wouldn’t feel the onset of winter quite as heavily as he had in the past.

A year or so after my divorce, in talking with an old friend who had lived with my ex and I when we were still married, I mentioned my ex’s Seasonal Affective Disorder, the only name he would allow for year-round mood swings that became more marked in winter. “Seasonal Affective Disorder,” our friend, herself a mental health professional, repeated with a hint of incredulity. “I always assumed he was bipolar.” She paused a moment, the crackle of the phone connection between us masking, I’d hoped, my sudden intake of breath. “You always seemed to keep him stable,” she continued, “although I can’t imagine that would have been easy on you.”

Her words, even a year or so after my divorce, rang like a gunshot. Bipolar? So others had noticed? I’d always assumed that my then-husband’s moods were our little secret, it being my responsibility to maintain our careful facade of a “normal” relationship even though much of the time I felt I was married to at least two (if not more) different men. My ex always refused even the suggestion of psychotherapy, even when he was the most unhappy, insisting that he didn’t want to change even his darkest moods since they were, he assumed, the source of his creativity. But had he agreed even to a diagnosis, if not treatment, how might that have changed the trajectory of our time together?

Whether or not my then-husband was bipolar then makes little difference now: we both have moved on in the five years since our separation and divorce. But even the mere suggestion that his moods had a Name–that there was, in short, something other than me to blame for his volatility–feels like a crucial piece in a puzzle I’ve spent the past five years poring over. One of the reasons you don’t get “over” a divorce, I’m learning, is because it stays with you like an unsolved mystery: no matter how many times you go over, again, the facts of the case, you’re still stymied by the simple question of “why.” Divorce marks an end, and it also marks the possibility of new beginnings…but it also leaves you with unanswered questions, a maddening lack of closure that no court-date or notarized document can ever sufficiently seal.

If there was a simple medical reason for the disconnect between my ex-husband and me–if any of a number of pharmaceuticals could have calmed a character quirk I spent nearly thirteen years thinking was My Fault–I can finally, five years later, let myself off the hook. I didn’t “fail” my then-husband because I couldn’t keep him happy; I finally left that relationship because I ultimately came to believe my vow to remain constant “in sickness and in health” didn’t apply to a sickness my partner refused to investigate, refused to name, and ultimately refused to treat.

Are we beholden to help someone get well if ultimately they don’t want to be well, or if they define “wellness” differently than we do? Are we beholden to make ourselves sick, too, while tending another’s unadmitted illness? I understand my ex and his wife have moved to the Midwest and now have a child, and I find myself fervently hoping they all are happy. Perhaps my ex-husband’s second wife is better equipped than I was to withstand his emotional upheavals, being more flexible in the face of ever-constant change? Or perhaps a child who grows up walking on the water of her father’s moods will easily adapt and acquire the sea-legs I never found? These are the questions–slightly different now, but still unanswered–I find myself asking five years later, no closer to closure, as I consider my divorce in retrospect.