as someone who is now quite firmly out of my 40s, i can say:

if you meet someone in their 50s (or 60s! or older!) who seems like they have their act together and are cogent and aware and witty — that is the result of a LOT of work, or a lot of discipline, or a lot of BOTH. you need to respect that.

i feel like i am at my intellectual apex and there is nowhere to go from here but to follow the diminishing parabola downward.