If a cat likes rubbing up against you are they always like that and how do they become that way?

I don't own a cat so I don't know but every now and then I'll see a very friendly cat on the street. It meows, comes closer, and I know its friendly and just wants to rub up against me. Normally that is the exception with most cats because they just run and don't let you come near them.

If I got a cat the ones that rub up on you is the kind I'd probably want. Still, I don't know if they tend to just be like that all the time and if you have to socialize them to do so or if it's jut a particular cats personality.