i dont think age has anything to do with it.. we all go through a grieving stage when we become parents because we are parents we are no longer free to do what we want.

but you are right in that soon enough your kids will be old enough to go and stay at peoples houses and you can have soem "free time". and you may have a free house before you are 40( i know that will sound like ages away)but it will fly past and you will still be young and active!!