If I take your car, without permission, it is stealing it. Very obviously you have been deprived of your car.
If I stay in your hotel, and then decide not to pay my bill, I have deprived you of the 1. the overhead associated with a person's visit and 2. revenue that room otherwise could have generated.
Now here is the question: when I copy your song, am I depriving you of anything? All the electronic devices are using resources paid for by third parties. You can still sell your song just fine, my act of copying has in no way prevented you from selling the song to other people. I may or may not have bought the song, so it is questionable if I am even depriving you of money you otherwise would have made (assuming no-fee copying, e.g. torrenting).
So, all that explaining to get to a "maybe" answer to "did he take away your stuff?" when applied to copyrighted data (a song). Now, there is some more nuance than even that: if I sell your song, I am obviously depriving you of money people are willing to pay for it. If I give away your song tho, there is no money I am depriving you of -- the people who gave me $0 are not guaranteed to give you the asking price without my giveaway. Further, how much of my giveaway is made up for in increased popularity? Could I charge back with a "stolen services" suit, declaring that my giveaway of your song helped push it to number 1, therefore you owe me marketing fees?
Basically, yes, some people get caught up in the legal definition aspect, but that is because the legal definition argument closely mirrors my question of "did he take your stuff". I do agree though, that maybe we nerds should come up with a good way of discussing it w/out invoking lawyers anyway.