How I envy the younger guys!
So let me qualify this first:
I am 70+ years old, but don't look it, and can manage 2 or three in one day. Think in one 24 hour period last year I did 4, but at my age it is a bit foggy.
At this point in my life 2 is a good number but not at the same time. Yes, I still go for twofers but usually can only mange to finish with one of them, but still can make both of them happy.
If I go for a second pop, it has to be a couple hours in between for recovery time, and this is even with or without the little blue pill. Even with the blue pill I don't see much, if any, difference.