On how you look at it.
Do you think a quarter-life crisis is an actual thing? I’m 20 years old and I feel like my life is over.
Your life isn’t over. Your childhood is over, and you just don’t know the difference yet.
As for whether a quarter-life crisis is an actual thing, sure it is. You can have an existential crisis at any age, and it’s perfectly reasonable to freak out in your early twenties when you suddenly realize that life is one big grind.
That’s no excuse to wallow in it, though. You’ve only got a few years in your early twenties when it’s culturally acceptable to screw around trying to find yourself. Don’t waste them being filled with angst and ennui.