can someone tell me without spoiling

P3R is my first persona game and i love the music and listen to it almost everyday (i dont listen to the part i've not done) why do song have such sad lyrics like i'm in september and ken just tell me ' yeah you're almost an adult and i hope that if anything happend to me you will take care of ''HAMBURGER'' " why do i feel that makoto wont live to see the end someone help (also i'm afraid for my body shinji i think he's the best and the fact that he knows about the "mad" persona scares me)