I feel like the people who are saying they are virgins are trying to justify it or using it to be self-deprocating. I don't think anybody needs to explain themselves to anybody. It's fine to be a virgin, and it's also fine not to be.
I for one lost my virginity at 18 and never regretted it, never looked back. A lot of people regret their first time (and a lot of subsequent times also) because they weren't special enough or with the right person. That was never particularly important to me; I don't even remember the name of the guy who has mine. But we both had fun, neither of us were using each other (or maybe we were both using each other, the line is blurred). Either way, no harm no foul.