12 and 14 years is a solid run, sorry to hear about it though.
Yeah, I mean... a lot of people would be happy to get a 10+ year run out of any given fish. Apparently 6 - 10 years is wild life expectancy for clowns, so you've already done them as well - or better - by them than the wild would, which isn't nothing. Yes, they CAN live 20+ years in captivity -
with good genetics - but I'd be willing to bet a lot has been learned in those intervening years, and your husbandry has improved such that the next may make it that much longer.
Also, apparently, the right - or wrong - nem can also make a difference... but, the 20+ - 30 year old clown is a rarity, and not reasonable goal for every given clown fish, as there are factors (like genetics) that are strictly outside your control.
It always sucks to lose a beloved pet/friend, but honestly in this case, it sounds like you were doing things at least as well as nature would have, and while we can (and should) always strive to do
better than nature in terms of our care and husbandry, the fact that yours beat natural expectations by a fair margin tells me you should have nothing to knock yourself for.
I get it though. After my last cat died, for example, I certainly wasn't ready to go straight out and get another... in fact we waited until my wife (almost) literally stumbled over one and came home and dropped a kitten in my lap.
So, I can't blame you at all for a pause, but... who doesn't love kittens or puppies? Or for that matter, teensy-weensy baby clownfish? Maybe now's that chance to start looking at one of those fancy designer breeds that have popped up in the last ~14 years that kept catching your eye?