It always worries me when someone refers to their husband or boyfriend 'helping' around the house. It may just be a turn of phrase, but it portrays a situation where you are responsible for the house, and anything he does is 'helping' you. But he's a grown adult and is equally responsible for the house. A child 'helps' around the house. Or a visiting parent might 'help' when you've had a baby.
You say he's highly intelligent. But if so, how come he doesn't realise that houses need cleaning, clothes need washing, food needs cooking? Of course he knows those things need doing, but he's lazy and he wants you to do them all. He cares for his own time more than yours. Maybe it comes from a place of sexism and there's a part of him that thinks it's 'women's work' or that, somehow, it's more natural or easier for women to do housework. I used to know a man who honestly thought women just enjoyed it. So effectively while he was on bike rides his wife was pursuing her hobby of housework.
Whatever his reason for not pulling his weight, you know he's lazy, you know he's happy to watch you run yourself ragged while he does nothing, you know this won't improve... you shouldn't have to tell an adult that housework needs doing, but in your case, even when you do that he 'forgets'. And then you're accused of 'nagging' when you remind him.
He either isn't nearly as intelligent as you think he is, or he's simply selfish and lazy. Do you want a selfish and lazy partner? (And they get worse, not better usually. And they become insufferable if you have children).
You've probably never dated anyone else. Certainly never been serious with anyone else. Please don't think this is normal. A good, healthy relationship that will stand the test of time and make both people (and any future children) happy is one where both are equally respected, both pull their weight equally in terms of workload and looking after the relationship, and where each cares for the other and wants them to be happy.