hahaha, it really depends, I think ;-))

eg. when people say "I think so", it can be 100% sure (with backup facts) for some, myself included. I won't say so to anyone at work if not 100% sure, as I had to be 100% (if not 120% ;-) dependable;  But it can be 55% to 90% sure for another person.  So one has to know the person well before judging.

But I have to agree with you, espeically when driving on the road, one can never trust the word "almost" (there), even when it comes from a GPS.