People still going on this mythological "prime years" - maybe, physically, there is a "tipping off point". But, intellectually? The data suggests differently, the more you learn and the tougher the skills you acquire as you age, the more refined you become when it comes to intellectual activity.
Your body may slow down due to it physically aging, but a person still in their 90s can complete marathons (check: Fauja Singh, Gladys Burill, Harriette Thompson, etc...). There are 80 year old powerlifters, etc... So, even physically, we can still get strong and still maintain our ability to run great distances well into old age.
In terms of intellect - as I alluded to earlier - if you continue educating yourself and deal with tough problems your crystallized intellect will probably peak at 60-70 years old (Hartshorne and Germine).
Your body may slow down due to it physically aging, but a person still in their 90s can complete marathons (check: Fauja Singh, Gladys Burill, Harriette Thompson, etc...). There are 80 year old powerlifters, etc... So, even physically, we can still get strong and still maintain our ability to run great distances well into old age.
In terms of intellect - as I alluded to earlier - if you continue educating yourself and deal with tough problems your crystallized intellect will probably peak at 60-70 years old (Hartshorne and Germine).