Expression meaning take lots of risks, have lots of fun, and don't suffer through old age. It is implied that the first half of the expression is what causes the second half.
Guy 1: I can't wait to be 65 when I can get medicare.
Guy 2: Oh god, I hope I never get that old. Live fast, die young.
Live fast die young (LFDY) is a slogan to encourage people to do what they want when the opportunity arises because tomorrow never comes. It is encouragement to take risks.
I have a theory it means the “contract”ends like that like with lil peep and juice wrld they both had thier birthday and died around the same week both young rappers get cake die young
Lil peep said he woke up with it but idk I think I’m getting to into it cause my ptsd keeps acting up from when I died lol I also died before my birthday n peep said nah he didn’t get his cake and I got like another chance at life get cake die young
Fuck it there’s no point in caring just let life take control and live through the motions and leave it all on the table cause tomorrow never comes there’s only today