why is it that when you lag and you say that, no one believes you?

So I have an HP laptop from 2013, and usually there are about 2-3 other people on my internet. This causes my computer to lag a lot, and I don't want people to think that i'm some kind of bronze player so i say "lag". Everybody is like "yeah sure" and it pisses me off because they are too stupid and stubborn to believe this. They really make me angry because I feel small, like some kind of lesser person to the other team because apparently i am a "garbage lying classic garen main". I sometimes get set off in chat, but fortunately no chat bans yet and only one more checkpoint to honor level 3 but still I think i am close to getting one I want some tips to use that will calm me down and just to tell all the stupid people out there that lag exists.