Likewise the original Gran Turismo on PS1 around 1999. Didn't bought it, instead it was lent by a friend, as I lent him Toca Racing Driver. Bought it when came out in Platinum edition.
Have every one of them (except Gt 4 Prologue), including the GT PSP and the step brother Tourist Trophy.
On PS2 there was a gap, as I only bought the console on the bundle with Gran Turismo 4, only buying GT3 and GT Concept 2002 many years latter.
PS3 was bought with the release of Gran Turismo HD Concept.
Already had the PS4 on release of Gran Turismo Sport, the game release coincided with the birth of my first child, It was a great paternity leave
. Right around the corner there was the Black Friday promos and Amazon UK had a great deal on the Logitech G29 (the wheel just became a bit less desirable because of the Thrustmaster/PD deal) and bought a PS compatible wheel for the first time.
Still with the old PS4, GT7 was the next in line.
GT Sport and GT HD Concept are the only ones I don't have physical copies (obviously the Concept was download only)