A lot of the law we take for granted about copyright is really just a complicated compromise that worked out alright given the limitations of older technology.

A lot of the law we take for granted about copyright is really just a complicated compromise that worked out alright given the limitations of older technology. It's not some moral ideal. What about recording a song off the radio for your personal use? Or downloading one off Youtube? Or inviting your friends round to watch a movie? Or doing that but asking them to bring food, or it's OK if they just bring money instead of food and you buy the food, or they just bring money and you don't buy food but you let them watch the movie in your house, or they can bring their own friends too, or you're a full-blown movie theatre? There are no clear-cut boundaries of "stupid" and "own", just a complicated balance to keep things working well, we hope.