When I was in college, I once (and by once, I mean “far too often”) decided not to study for a final exam. I would walk into the classroom on the day of the test, still trying to convince myself I could do okay. “Well, I’ve gone to every class this semester, so I probably picked some things up just by being there,” I would think. “Plus, I’m a little smarter than I look, I’m a decent bullshitter, and, umm, I’m pretty sure this professor likes me.” But no matter how many times I tried to tell myself the test wouldn’t be too bad, I walked into the final accompanied by a sense of impending doom.

Or, the same feeling I got whenever Tony Allen stepped onto the court wearing a Boston Celtics uniform. Allen returns to Boston tonight as a Memphis Grizzly, which seems as good a time as ever to rehash my feelings toward him. That is, if there’s ever a good time to discuss flicking off Doc Rivers every time Allen subbed into a game, or my intense desire to throw my television set out the nearest window, or knowing—just knowing—Allen was about to make the dumbest basketball play earth has ever seen. Remember that time Allen received death threats in Chicago? I’m almost positive they weren’t from me.

In all fairness, I’m too harsh on Allen. He brought positives with him, too. He was tough as nails, the type of guy you definitely don’t want to fight on a team airplane (I’m looking at you, O.J. Mayo). He would defend the other team’s best player every time he stepped on the court, and do at least a reasonable job. At just 6’4, he possessed the quickness, strength, pitbull mentality and versatility to limit Lebron James, Kobe Bryant or Derrick Rose. He was a pest, and he never backed down. Last season, he even became somewhat reliable. It was like watching the girlfriend who always used to cheat on you settle down. No matter how long she remains good to you, you always feel she’s on the verge of making another unfathomable mistake. Okay, maybe that’s not the best example. If you get cheated on that much, just dump the bitch. But what I’m trying to say is that Allen finally settled into his role last year. By the end of the season, when I saw him crying after The Game That Must Not Be Named, I almost liked the guy. Almost.

Alright, I’ve reached (and surpassed) my “Tony Allen compliment” quota. As a Celtics fan, I lived through watching Antoine Walker’s “I only take so many three-pointers because there are no four-pointers” shot selection. I experienced Rasheed Wallace, who never seemed to care about anything except launching ill-advised shots and complaining to any referee within shouting distance. I watched Brett Szabo, Marty Conlon, Gerald Green, Sebastian Telfair, and Vin Baker embarrassing the greatest franchise in basketball history. Yet Tony Allen was the one player who brought me the most frustration. And nobody was close.

Allen didn’t just make mistakes; he made impossibly dumb plays at the worst times imaginable. If the Celtics were tied in the final possession of a game, it seemed like there was a 90% chance Allen would commit a charge. If the Celtics were ahead by two points in the final possession, it seemed like there was a 90% chance Allen would foul a three-point shooter. There wasn’t actually a 90% chance of either of those things happening, of course. But it felt like there was. If my words don’t make sense, you weren’t a Celtics fan during the Tony Allen era. Allen didn’t just walk on the verge of destruction—he constantly rode a bike across a tightrope three miles above the ground.

The Celtics failed to sign Allen this offseason, and it’s tough to tell whether they really tried to. Danny Ainge said they wanted Allen back, but he signed in Memphis for a marginal contract (three years, $10 million) that the Celtics probably could have outbid if they really wanted to.

By all accounts, Allen’s been great this year for Memphis. He’s cut down his turnovers, continued his impressive defense, and remained a difference-maker because of his energy, athleticism and toughness. The Grizzlies blog Three Shades of Blue even wrote after a recent win, “Tony Allen. This guy, right now, is the undisputed leader of the Grizzlies.” Weird, I know. But with the way Allen’s played (combined with the way he played last year), it’s easy to look back and wonder why the Celtics didn’t re-sign him. Then again, watching games is a lot more relaxing now that he’s gone.

All things considered, should we boo Allen tonight, or do we cheer him? I know my answer. As moronically dumb as Allen could be on a basketball court, we never had to worry about his effort. He bounced in and out of Doc Rivers’ rotation but never complained, and even spent most of his bench time excitedly waving a towel in support of his teammates. When he cried after The Game That Must Not Be Named, it wasn’t just because he came so close to winning an NBA title and lost. It was because he’d bought in entirely to Doc’s plan, because he loved his teammates, and because he cared desperately about the Boston Celtics. Tony Allen, though he made a vein appear in my forehead where I never knew one existed, played his ass off.

So I will cheer Allen, loudly. And then I’ll thank my lucky stars that the next time he rides his bike across a tightrope, I won’t be rooting for his team.