What do you wish you had known when you were young so that you could have lived your life differently?
A Reddit user has asked people to reveal the best life lesson they learned too late - and hundreds of people have come forward and contributed to the thread.
Answers include everything from knowing the difference between being a nice person and a doormat - to the fact that sometimes bad things happen for absolutely no reason.
The majority of answers from Redditors were serious as they offered advice to both their younger selves and others who might be younger and reading the thread.
Some said that it took them a long time to learn that you shouldn't compare yourself to others all of the time - because you're always going to be disappointed.
A sombre piece of advice came from Auggernaut88, who experienced the sudden death of a family member, and said that bad things don't need to happen for a reason - sometimes they just happen.
8ltd took to the forum to say that love isn't always enough.
They had gone through life thinking if you loved somebody then it would automatically work out but it isn't true.
He added: "You need to put work into the relationship or else all the love in the world won't save it."
Another Redditor said they learned too late not to compare your current partner to your ex - as it does nothing but destroy something that could have been amazing.
Some people kept their life lessons short, with comments such as telling people to always get things in writing, marry carefully and realising that just because you can do something, doesn't mean you should.
Despite seemingly simple, these life lessons are complicated and will have taken years to discover.