what a question. seriously. my dad left when i was 8, disappeared and reappeared throughout adolescence, and finally vanished around age 21. i found him again....right around age 32, and realised i just couldn't deal with yet another vanishing act.
so, i vanished first.
when he died a couple of years later, my mom phoned me. she found out from a random google search that turned up his obit. when i called his current, and 6th wife, all she could say was "why didn't you ever call him back? you broke his heart."