The Importance of Self Awareness in Preteens

I have a five year old boy who has lately become very concerned with what his peers think of him. He doesn't want to wear his hat or mittens because someone laughed at him. I remember having those kinds of concerns when I was a preteen, but I'm surprised my son is struggling with this so early. It's hard to even do that for adults. And problem solving is, you know, as she said, not going to happen with the 16 month.