I've had that happen with what i assume was a hand lotion because there was a particular part of the lid that smelled.
I don't know why other people are treating you with so much disbelief. This absolutely can happen with people not thinking about how their habits impact what customers are consuming. With how many millions of coffee beverages that are served every day, it shouldn't surprise anyone that some small portion are handled improperly with poor hygiene. It also shouldn't be overly surprising if you've had it happen multiple times because you likely visit the shops near you. Such an event isn't random and is the result of someone's bad habits.