Sometimes I change really quickly, two or three times in a few minutes and that can unnerve people that know me well, especially when I don't notice. That was actually how I started to figure out I was changing, from my friends commenting on how it confused and unnerved them.
Strangers notice sometimes when I'm walking down the street, or in waiting rooms. My little one comes out in public a lot more than he used to and I think that confuses people. He's usually very well behaved and lets the adults do the talking but he will say out of place things sometimes and his voice really sounds little. I can imagine it's surprising coming from a grown man with a greying beard.