What common mistake made by young people is they can always find time to gain money for their selves since they have plenty of time left in this world that's why they set aside those important things and take first what they can make them enjoy their life. YOLO mindset is the one actually killing their dreams so if they don't realize that certain bad things would ever happen if they didn't prepare for their future then for sure they would regret once they realize that they are in late stage on their life. There's no regret will come first as saying says so to avoid getting broke and sick when we get old much better if we are ready then prepared something so that when we became old and retired already we can still live a comfortable life and we can't bother anyone with this.
I feel like that is reasonable to want to live life first though. If you keep on postponing life, then you could always have something bad happen in later life and then suddenly you would not only spent all your life on saving, but then lost that saving because of something bad as well. What would you gain from that? Not only you would be poor but you also could say that you never lived neither.
I am one of those people, I stayed at home all my life and didn't do anything, I didn't even live a proper life, I lived a terrible life when you look at my memories, but at the same time I have no money at all, literally zero, I am fully in debt. Don't be like me, I wish I never saved and just lived a very adventurous life when I was younger.