It's better to make notes in your own chess program or DB, but the notes section here is better than nothing. Keeping notes helps you remember critical moves to either play or avoid that you may not keep in your head overnite or longer
Do you use the notes function during your games?

I've used them before when I have 30+ games going at a time. I usually make a short note of what my plan was going to be if my opponent plays a certain move.
It helps to keep me from blitzing out a response, especially if it's a longer time control game (like 14 days) and I haven't been thinking about that particular game in a while.

Well, I suck at chess, and have no DB. So, if I go through a series of moves that I think I might not remember, I'll paste it from the analyze board to the notes. I'll admit I don't do it often. And, I've pasted some that are ten moves deep, only to erase it when my opponent made a different third move.
If you're only analyzing here on c.c, it can't hurt-unless you move in a game without seeing the tiny red asterisk, as I have done.
If so, how has it helped you?