At 31 my memory isn't nearly as good as it was at 18. I remember I could sit through my classes, do none of the reading and still get perfect scores on my test

At 31 my memory isn't nearly as good as it was at 18. I remember I could sit through my classes, do none of the reading and still get perfect scores on my tests (as long as the material was covered). However, my ability to internalize and relate complex ideas is MUCH improved. I'm way better at abstract math now, I'm not sure I would have even had the patience for it previously. Another thing to consider: many people get minor bouts of depression in the winter. Generally your memory is worse while depressed.