Do you ever feel like your not actually on the toilet while shitting on the toilet?

Do you ever, while shitting on the toilet, wonder; what If in reality im not actually sitting on the toilet? What if all my senses are telling me i am but in reality i am. For example, in a public space, on a public transport, or somewhere else? The worse thing about this Is that you wouldnt even know you're actually, for instance, sitting on a fountain in Cental Park shitting with your underwear down uncapable of doing anything to be aware of it.