confused about this

Ok when I used to work at a hotel I had this guy co-worker who everyone liked and was funny too. I caught myself thinking about him in the beginning as we worked together then ALOT more soon after I quit. The thing is, I had no sexual attraction towards him whatsoever. I know this is a bi sub but I wasn't fighting any sexual urges I just couldn't stop thinking about him and wishing I got to know him on a more personal level. So with all that said, what do you guys think is/was going on? Was this a crush? Or just an admiration of a good worker that was very likeable? I don't know what to make of this. For the record, I identify as straight male.