I am a 20-year-old student. Not long ago, I heard a famous cryptocurrency expert in Korea on YouTube.
He said, "Bitcoin investment seems to be late, to be honest. I'm sad, too. I think 2018 was the last chance for ordinary people."
This makes me feel depressed. That expert started investing in bitcoin in 2013, and he encouraged his acquaintances to invest in bitcoin, but at that time he said everyone thought he was crazy.
Honestly, as an ordinary college student, the price of bitcoin now feels too much to buy.. If it's the price of the early 2010s, I might have bought it through a part-time job..
I'm so pathetic and depressed because I didn't know Bitcoin quickly. What should I do?

You shouldn't feel depressed, you're lucky you learned about Bitcoin now! There probably won't be any parabolic growth but buying small amounts regularly and hodling for at least 2-3 cycles will eventually make you quite a wealthy person. It's never late to invest in Bitcoin.