How to keep track of so many numbers/information

I'm relatively new on the buyside and I think one thing I'm struggling with is keeping track of so many different numbers. I keep hearing the PM asking some of the more experienced analysts about a given name, and they just fire back the answers, including lots of numbers or other data points..even on names that they haven't looked at in a while. I'm just kind of trying to figure out what's the best way to retain so much information. I think i'm getting pretty good at putting together investment memos but I'm not sure how best to actually "own" the material...any input from more experienced/smarter monkeys would be greatly appreciated