Peter Schilling's 'Major Tom (coming home)' is the first 45 rpm single he ever bought, and he even bought two, giving the second one to his neighbor friend as a gift. There wasn't anything symbolic about it at the time; they must have spent a recent moment appreciating it, and he wanted to return the favor after the slightly older friend had loaned him some albums.
In retrospect, he likes this single as his first. It represents his gravitation towards songs based on their merit, rather than their chart status. A fluke hit (kissing cousin to Nena's '99 luftballons') that retells Bowie's 'Space oddity' with more synth parts to beef up the futurism, 'Major Tom' also boasts a killer chorus with an irresistible outro. The b-side, sung in German, didn't do as much for him, because the plot is so good, like a Ray Bradbury short story.
Decades later he danced to the song (the original, not the diluted 1994 remix) for the first time in a nightclub setting, and it was strangely emotional and rapturous. A homecoming, of sorts.