Need a guy's input on a dating question 45 yr. old?

I met a guy a few weeks ago at a over 35 singles dance. and we really hit it off. He called me twice during the week and we went out the following fri nite. chatted and had drinks and came back to my place. we kissed and it was "electric". We kissed for quite a while. I know if I said "let's go upstairs" he would have, but I just met him and said "you have to go" He left and called me during the week as he was going upstate to visit his brother and nephew. He said he'd call me when he got back. That was Monday and I haven't heard anything. I could call him, but if he's interested and said he'd call I figure he would. Why do you think he hasn't called?