'Influencing' people, without anyone having a clue I did it (sometimes 'on purpose') ...
(Long answer I know but...)
For example; years ago, I routinely would go to a lecture, sit down next to people I didn't know, with intention I would routinely do a few little 'experiments'; I'd subtly copy someone's (near/next-to me) body positioning for awhile (it develops an unconscious 'rapport') then I'd purposely stop copying them and without fail, they'd (unconsciously) then start copying me ...
The funniest thing was one time when the girl I had done this to for nearly an hour, realized she was/had-been copying me ! I had purposely positioned myself in a posture that she hadn't (yet) assumed, and was subtly 'out-of-the-ordinary', she looks over at me, notices my slightly odd positioning, then looks at her own position, realizes it was identical and with an embarrassed ("oh crap!") look on her face she quickly changed her position!
Then recently (not so much the body-language influence this time, but); I took a course (dozen people, around same conference table). Last day of class, like others, I did a final little 'speech' but unlike the others, everyone stood and clapped for me/my speech.
Near the end of last class, as we were all getting up to leave the Instructor asked me to stay behind, so ... she asks me "did you notice ? how everyone was following you, your every word ?" I answered "yeah sorta" Then she says, "I don't know how you do it, but in all my years of teaching courses like this , I've only seen that talent in maybe a couple of others and they went on to accomplish a bunch of influential things, so Please whatever you do, don't let such a special gift go to waste !"
Sad part is though, it is a "secret talent" as most people, especially those the nearest to me (close friends, family etc.) just know it all as 'me being me'. And sometimes even worse, are the few that recognize it and start undermining me for it. A 'friend' of mine said it one time like this (when I asked him why he didn't introduce me to a group of people that he knew but I didn't) "ohh I've seen how you are with people, you don't need any help!"