My daughter is fascinated with hair. All kinds of hair. When we go out in public she'll ask people she doesn't know if she can pet their hair. She especially loves buzzed mens heads with a small growth. She will pet them and squeal that it tickles and reach back for more. She'll run up to anyone and ask very loudly in a crowded place if she sees hair that she wants to touch, "CAN I PET YOUR HAIR?!?" It's just so freaking weird! She'll even tickle your eyebrows if you stay still long enough. She's almost four now and I'm trying to impart to her the difference between family and strangers because right now she tells everyone "I love you! See you later!" when parting and wants to hug, kiss and touch everyone she meets.
Kids all have their "thing" and I'm sure he'll grow out of it. Just the other day we had the plumbers over to fix our toilet and Chloe stood back and said very loudly, "Mom those are strangers!" Then softer, "I'm not supposed to pet their hair..." Then loud again, "Can I give them a kiss?"
Another facepalm moment, brought to you by my kid.