How to not give a fuck?

So I'm in my college years and I have to commute daily by public transport, and people especially teenagers stare a lot at me and talk loudly about my height and compare themselves...I know I shouldn't be bothered by something like this but it makes me uncomfortable. What should I do so that I don't become an insecure guy?

Edit:- Also I'm skinny for my height (78kgs) and it makes me look even more tall

Sorry for my English...