It was a big hit to my confidence, especially as a teen. I also felt it prematurely "aged" me - I used to joke that I turned 28 on my 18th birthday.
It is nice that there are successful/attractive men who are bald to point to, but I was more often compared to Moby or Billy Corgan, not exactly sex symbols.
It all seems silly in retrospect but it felt very serious at that age. I'm so used to it now that I don't even think about it. It helps that I'm old enough that being bald is "age appropriate" and I stick out less than I did in college.