I have noticed a difference in trips since when I took it at 16, to when I take it now (20). Not in the intensity of the trips, but in my ability to focus my trips. When I was younger, my trips were amazing and I learnt so much, but my head was all over the place and I couldn't focus enough to hold decent conversations or even really keep my thought train going in the same direction. Now that i'm older, I find that I can really focus on things and get more out of it. I've given acid to several first timers, and the younger ones (when i was younger too) found it all very confusing and weird, whereas recently I gave it to two 23 year olds, and I was really suprised at how together they were. I used to think that was more from experience, but now i think its more of an age thing