Can you fancy someone who've know for a day? ?

right I am so confused. Met this new guy at work today. Now I'm actually fed up with men at the moment and wanted to stay single. Now he asked me my name and indroduced himself and shook my hand he was really polite and friendly and smiling a lot. Now he's good looking but noway the type I go for. But after I met him I couldn't get over what a gent he was and I can't stop thinking about him...you can't fancy someone after 6 hours of working with them right? I mean if we got to know each other better and I do like him and he likes me then ill so go out with him!