why did he not call me back? usually tons of calls now nothing.?

so I went out with this guy on the weekend and we spent 8 hours together way into the night and he said he wanted to see me again, and told me how much he liked me and everything. and he couldn't wait to see me again. so any ways i decided to call him and not a word. nobody is that busy!

anyways this has never happened to me before, usually phone just rings of the hook with multiple text messages. even my ex calls me more than he does and have received calls from everyone else except for this guy. i never waited for a phone call before. is he dead, is he in a coma?