Why do people make fun of teens for being in love?

I just got into a relationship with my best friend of so many years and we both told each other that we love each other. I was really happy, but then my mood went downhill because one of my aunties was visiting and was telling me how teenagers don't know a thing about love and to wait for it as an adult. EXCUSE ME? You are literally a divorcee ma'am! There's nothing wrong with being divorced by the way, but she left her husband because of the fact there was no love! I know she means well and all, but auntie, why you gotta ruin my moment?? She also looked a photo of my bf and seemed shocked I would go out with him (my bf is a skater/motorcycle guy). I don't care what she thinks though. He's very mature and treats me like a princess. Why do older people want to rain down on our happiness/relationships? Like, c'mon.