Why would a guy be so affectionate & considerate to a girl he didn't consider dateable?

The last guy I was involved with was very affectionate, considerate, an attentive conversationalist. He liked to talk for hours on end, hold hands & cuddle, did not paw all over me and ually respectful. Pretty much blew most of my the guys I date and even some boyfriends I've had out of the water. He didn't consider me dateable, though ... Why would someone act like that? I'm trying to wrap my head around it so I can move on to the guys who want to date me who aren't as enjoyable to spend time with.