thought Id give my perspective...
during my life time I have had quite a few sexual partners. in my early teens and 20s I was obsessed with vagina. it was a massive driving force and definitely overrode a good portion of my decision making ability.
in my early thirties that drive was still strong however it lacked the vigor I had in my twenties. I began to become more focused on my goals and financial success. vagina was still a priority but lower on the totem.
late thirties, sex became more typical and monotonous. it became a matter of fact and I had the been there done that mentality when it came to a sexual experience. I still enjoyed sex, but the amount of time and energy that I wanted to dedicate to obtaining sex was dropping. my goals and financial success become much more satisfying then sex.
Im in my forties and the drive while still there does not motivate me nearly the same as my 20s. in fact this is probably the best time in my life. the amount of time, energy and money I put forth trying to impress women was truly astonishing to me.
for me sex is like an apple. when I had my very first apple as a child, it was the most delicious thing. as I have enjoyed many apples throughout my life, the apple has become common and lacks the luster of the first time. sex was amazing the first time, but after many encounters its pretty much at the same level as that apple.
while I am not a eunuch, the change in my sex drive has allowed me to improve my life and see past what is at the end of my penis. I wish it happened sooner. the amount I would have accomplished would have been awesome.