I'm playing a D&D 5e character in Curse of Strahd who's currently an Arcane Trickster 7 / Divination Wizard 2. We're playing online via DnDBeyond. Today I died, and it wasn't until 3 or 4 turns later that I realized I could have used Uncanny Dodge to halve the damage from the last blow I'd taken while conscious and kept myself from falling unconscious in the first place.
This is the second time something like this has happened; a few months ago I only survived because a Warlock in the party begged his patron to save me and, on a 99+ flat d100 roll, rolled a 99. But then I realized later that I'd had inspiration the whole time and could have just used it to try not to get into the deadly situation in the first place.
I don't know whether it's my ADD or what, but I hate that this keeps happening. I've tried making a list of all my abilities in a Word document so as to have them at my fingertips but then I forget to look at it in the heat of the moment. I'm going to try printing it out and making a policy to glance at it every time I take damage or something, and keep my fingers crossed that I can remember that policy, but knowing myself I don't love my odds.
I'd love to hear methods forgetful or ADD players have successfully used to remember their characters' abilities. My party is planning to revivify me next session, and I'd love not to keep having this problem.
EDIT: With the insight gained from Ryan C. Thompson's comment on this question and from TheDragonOfFlame's answer, I've come up with a method that works for me. Since the things I keep forgetting about tend to be reactions (either in-combat big-R-Reactions or out-of-combat small-r-reactions), I've written down every ability/item/whatever I have on a list headed "Things I Can Do When Bad Stuff Happens." I look at this list whenever I get hit or when, well, bad stuff happens. It's a short enough list that it's not overwhelming in the moment, and the trigger (something bad happens) is noticeable enough that I don't forget. Thanks, everybody!