So, the plan is to work super hard until you are ~40, only to die in a car accident at 35?
Don't plan to have fun later, because later may never come.
Don't plan to have fun later, because later may never come.
You didn't exist before you were born, so you had no idea about anything.
You "die" when you go to sleep.
So we could say most of it doesn't matter - of course if there isn't anything after our living here.
The point of the commenter was that if we wait to have fun til later, there may not be a later. Life is about striking a balance of having fun now and sacrificing now so that you (or your family or community etc) can have fun later.