Bizarre key problem

So I got home tonight and pulled out my key and was reaching for my purse and the stereo began playing again and the "Remove key" message displayed on the dash. I had the key IN MY HAND! I didn't know what to do actually so I just stuck the key back in the ignition, turned the car back on and turned it off again and removed the key. It seemed ok but this has me worried. I swear I was not a) imaging it or b) drinking tonight. <g> Anyone ever experienced this or heard of it?

I'm thinking I should probably take it to be checked before it happens and I can't turn the car off at some point. I'm a little worried however that they will think I'm a nutbar.