[know.your.why]

Males, on the other hand, continue to create new sperm for most of their adult lives..........

Ok. I'll have plenty of ammo. Just my barrell looses its temper...and what...needs to get case hardened and re-rifled?

[Secret Agent Man]

Nerve sensitivity declines and you just require more physical stimulation than when younger. You also need visual stimulation that works for you, and that still means a woman that looks good to you, generally a still fertile woman has those visual traits.