It's not that I don't remember how a student's acted, both positively, and negatively, from day to day, week to week, only that I can't hold that for or against them in how I interact. I have to be warm and welcoming to that kid who threw a chair across the room. I have to keep that child in if they're playing up today but never have before.
I think I'm actually pretty good at doing this. It turns out my persistent ability to live in fiction means I can see each day as a new opportunity. Alternating alternative realities, one might say. Yeah, yesterday sucked, but today? Who knows? It could be spectacular.