'Mistakes People Make In Their 30s'

Quora users discussed lessons they learned in the thread: "What is the biggest mistake you made in your 30s and what did you learn from it?"

Here are some of the best responses:

They don't spend enough time with their aging parents.

Entrepreneur and blogger James Altucher, who is now 46, writes about a particularly difficult memory for him: "When I was 34 I hung up the phone on my dad in an argument and never returned his calls. Six months later he had a stroke and died.

They put their career ahead of family and friends.

"Don't just work. Make memories. The older you get, the harder it is to make meaningful relationships. Foster those while you're young," writes Microsoft product designer Michael Dorian Bach, who is now in his late 30s.

They miss the chance to have kids.

CEO coach Alison Whitmire shares a personal story about how she took getting pregnant for granted in her 30s and chose to pursue a new career opportunity instead of trying to have a child. Years later, after a failed pregnancy and then a failed marriage, she remarried and had a baby at 43. She realizes now that no one is ever adequately prepared to have a child, and if you want one, it's best to do so before it's too late.