Ive had that happen to me too, it can be quite annoying.
When i was younger id often find that after rollerblading i couldnt imagine myself walking without blades on.. The more i focussed on imagining just walking the more id feel the sensation of rollerblades beneath my feet.
This used to happen with many things, i remember for instance thinking of being tied by my ankle to a tree, after imagining myself being cut free the rope instantly reattached itself to my leg, i then spent a long time battling this imagined rope, attempting to stop it from ruining my internal imaginings by burning it or running away, only to have it beat me each time.

Quite frustrating and hard to stop once its started, although i have much more control over thoughts than i used to.