Man Up in a Balloon.

Claude, an elderly man living in the 1960s, believes he is dead, and cannot explain why his body is lingering in the living world. He has tried to 'get rid' of his body multiple times to no avail. Claude is just a particle of air in his drug-transcended offspring's lives. Whilst the family prepares for his grandson Florian's balloon-filled birthday, Claude decides to attempt using young Florian to help him meet his end, in order to allow his body to follow his mind into death.