From regretting things said to your spouse this morning, to wondering what might have been if you'd taken a different path 10 years ago, we spend our lives looking back wishing we could change the past.
A conversation that began in the HuffPost UK office yesterday about what we wish we'd known as youngsters, ended with a list of thoughts from our readers that made us laugh and cry.
The range of responses made it clear that this is an issue close to everyone's hearts.
Read the touching, and sometimes hilarious, pearls of wisdom shared by our Twitter followers, when asked what advice they would give to their younger selves.
Do you have any words of advice for yourself? Let us know in the comments section...