Swimming with sharks....not!

A couple of days ago we had a really good strong sea with decent sized waves so I went swimming.
It was cold as autumn is just around the corner here but after a few minutes it felt fine and the waves were fun to bodysurf on.......................after a few runs I suddenly had this image of the picture in this comment and thought .........what is going on?
There are a few sharks around here but usually down the coast and the odds against seeing one in the surf next to you are about a zillion to one against.
I like to scuba and have been amongst sharks in the Indian ocean and other places, but that's different as one is not feeling so blind and vunerable.
Something about one's mind, which likes to jump to improbable scenarios, and mine had managed just that..
My thought is we are such funny people, humans spend so much of their time worrying about things we cannot a) alter or b) seldom if ever come along as we imagine.
Thought for the day "stop thinking and live in the moment".
The rest of the swim was great except I was so busy thinking that a large wave caught me unawares and I managed to swallow half the ocean while trying to dive under it...................as I said thinking is oftern not very helpful!!