People that take off their shoes and socks in public to make sure that they can give their feet a good scratch with their overgrown fingernails. Then, calmly put their shoes and socks back on and start touching things. I had to witness this and try not to vomit while on an airplane. And it went like this:
Man in his 50's takes of his shoes and socks. He aggressively digs in to those itchy feet and gives them a good scratch. I try not to cringe and attempt to keep reading my magazine. I am sitting directly behind him in the aisle seat. He is probably glad to have the aisle seat. Do you know how I can tell? Because he takes his bare foot and starts grinding it into the carpet, leg fully extended into the aisle, because his nails were insufficient scratching tools. He really got into this. His grunts of pleasure were really quite enough to freak me right the hell out. Finally, he is done molesting the carpet and gives his foot a little love tap before he covers them once more. I don't know about any of you, but this idea would never cross my mind as being good and odd personal itching definitely is something I don't like.