Through his condition he has never been able to lay down in a bed like a healthy person. He has always had to sleep upright. Through the years he has SO longed to experience being able to sleep like a healthy person. So at the end of the film, he finally decides to experience it, despite knowing that sleeping flat will most likely kill him (it'll cut off his airways). You see him remove the pillows that keep him upright in bed, to leave a single pillow there. He lays down and looks so serene. As he lays there Barber's Adagio For Strings plays. He struggles for breath after a moment and closes his eyes.