Once I made a trip to China. I was going to be there for two months, crossing spring and summer. I had only my stuff in a carry-on. my mother wanted me to bring back two big suitcases of stuff for her relatives. I would meet her at the airport. I had dropped off a sweater jacket earlier with her, and somehow, of all the stuff, she found my sweater to be redundant. So she took it out.
I think it was at most 1.5 lb to 2 lb.
That is just one example not so embarrassing to write out. There are much worse ones.