A man is saying he thinks a lot about you during the day when you are not there, fantasizes about you during the night and is curious about you as a person. Its not necessarily that he loves you but more that he feels the need to be around you. Its a way of saying he is willing to open up his mind and one day his heart to you if he continues to do the above. At least that's when a man's man (mature) tells you so.
When a boy-man (immature) tells you that its saying he cares about you but is unsure about his feelings for you romantically.
Up to you to know whether the man saying so is a boy-man or a man's man though to be sure.
attached. Usually a term used in highschool but ok. It means from a guys perspective, that you're the only girl he thinks about. It's a term of endearment that shouldn't be taken in a negative fashion.