I get that it may feel insulting if someone offers you help when you're perfectly capable of doing something by yourself. I used to get upset about this, especially in my teens. I'd think 'Why the hell does this person think I can't do this by myself? Do I look like a weak child? Who does he/she think he is? I can take care of myself!'

But when I got older I realised that most people honestly don't think that way, and are in no way trying to be insulting. So honestly, 'I'm not a fucking toddler' is too harsh a reaction imo.

I mean sure, if some guy insisted on carrying the smallest things for you just because you're a woman and therefore naturally delicate, then it's sexist and insulting. Or whenever something needs to be done on a computer, a guy insists on taking charge because women are bad with technology (my dad used to do this). That's sexist and insulting.

But someone offering to help lift a heavyish looking object? I can see how it's sexist in a way (because it usually takes something far heavier for someone to offer a man help in carrying it), but to say that it's insulting is in my view a bit too far.

It's like holding the door for someone. Does it mean they think you aren't physically capable of opening the door for yourself? No, they're just trying to be nice. Just like they're trying to be nice when they offer to help lift a heavy object, not because they think you wouldn't be capable of lifting it, but simply because it might make it easier for you if there's a helping hand.

The kind of sexism that women should always be offered help and men should be able to do everything themselves (or only get help from other men) is also so deeply ingrained in our culture that most people are going to adhere to it without thinking. It doesn't mean that that kind of sexism is alright, and that we should perpetuate it, but it also doesn't mean you have the right to yell at people for it. Just politely saying 'no thanks, I can handle it' gets the same message across.