Being the tortoise means you have plenty of time to really notice and appreciate things, things you never saw before, things you never thought before.
First, I realized that the warm feeling I get from "the best" person is partially because of him and partially because of the person I am around him. I like the way I act, I like the things I'm learning. So, even though I don't want this relationship to end anytime soon I am not panicked trying to hold on too tight. One day we might end up just being friends, but I will still get to be this person; maybe even a *better* person.
Second, he has not shied away from flirtation, romance, pillow talk, future plans even though he only wants to get -this- serious. I think most men would avoid these sweet somethings in order to "not give the wrong idea." And that's probably for the best as most women wouldn't be able to keep the two things separate; he'd text sweetly out of blue and they'd think, "He actually does want to be my boyfriend." But because of item First, I get to enjoy those delights of a new relationship, while still keeping my head on straight (mostly).