22:48
First is that it should interact nicely with homotopy and suspension, then you have this technical condition about continuous maps, and a last one I forget
If you add a fifth one about the 0 cohomology group you reduce to the standard one that people first studied
But other theories come up if you kill that one (other conditions don't make much sense to try to break)
K theory is one of them, and it's associated with these things called vector bundles
Vector bundles are a way to formalize the idea of "continuously stitching" vector spaces to a topological space
And re topological spaces, it's not really like vector spaces. Those are a certain type
In R^n you have the notion of neighborhoods of a point, like you need to have a ball. Topology is basically that sort of thing