Would you invest your money or spend it having fun?

So this question came to me when I answer this one

Im young-ish and earn enough to have a really really great closet/shoe rack and a enjoy myself fully. However I have so far invested half of my earnings and the other half I do have is spent in necessities. I do of course spend money on shopping and going out with friends but I could do more and have an even better time. Some of my friends say I should really be spending this money at this point in my life. I think of it in the opposite way: I’d rather save/invest now when I can afford to.

What do you do? Or what would you do in my situation?