Have you ever had a crush on someone, but they didn't like you back?

I mean yeah, this is kind of a really blunt question, but if it did happen to you…how so?
I know from my own experience that it was one I actually learned from.
We knew of one another since junior high, but we never spoke. I started to like how he carried himself, and I started crushing on him after having him in a class. I also liked how he knew how to dance. He soon found out from my suppose to be “wing girl” that I liked him. I mean it was kind of obvious. He laughed it off and told her I was just a friend. Ever since that day, it just became really really awkward. Now he’ll do like awkward and weird things just to make the situation more awkward. UGH I still somewhat feel embarrassed about it all. Please share your personal experiences, if you had any like this.