because they have something in common. both about space, both filled with an overly-romanticized message.
your friends must be pretty thick to not get it. all he is saying is the first rule of whatever kind of physics it is that says that matter is neither created nor destroyed.
sorry i'm not 12 and am not impressed by a flimsy message made strong by setting it to pretty pictures and music. and karma? oh no! if i wanted a lot of +K guyzzzzzz i'd just post funny videos all the time and pictures of hot girls. luckily, i dont give enough of a shit to waste my time doing that