Honestly I don't think whoever is doing that is trying to be condescending. It sounds as though you may have elevated the importance of losing one's virginity into a life defining moment, so what those people were probably trying to say is that losing it isn't as big of an event in life as that.

The first of anything is memorable. The first beer, first kiss, first fistfight, first date, etc, but a person's life or who they are doesn't change just because they drank a beer, or kissed someone, or got in a fight. Similarly, the first time someone has sex they aren't going to be ushered into a different world. Most likely they would think "That was it?" because it's been turned into such a massive rite in Western culture that the reality cannot possibly live up to those expectations.

I don't think those people were saying you don't feel about it the way you do, or that they were attempting to diminish or disregard those feelings. They're just trying to put it in perspective as individuals who have had it, and so know it's not as life-defining as you seem to be thinking it will be. The person you are now is the person you will still be after losing your virginity. Speaking as an observer who has watched people go through the dating process, into marriage, then into the parental role, what changes you is not the act of sex. It is the act of sharing something with someone. Of choosing to dedicate your life to working alongside someone, rather than moving through life alone. That choice can be made totally absent of sex.