An update on Trigger's broom

In Only Fools and Horses, Trigger famously opined that, in his job as a council road-sweeper he's had the same broom for twenty years... just with seventeen new heads and fourteen new handles.

Only a totally unrelated note, I've been running the same bike for more than thirteen years, but with a few new heads and handles... here's an update on the current state of play:

Still original	Replaced or upgraded
Frame Fork Headset Seatpost Seatpost clamp Front derailleur Rear derailleur Gear shifters Brake levers Brake calipers Grips	Wheels (M/U) Tyres (M/U) Inner tubes (M/U) Cassette (M/U) Brake pads (M/U) Brake cables (M) Shifter cables (M) Bottom bracket (M/U) Chain (M) Crankset (M/U) Chainrings (M/U) Handlebar (U) Pedals (U) Saddle (U) Stem (U) Bar ends (U) Top cap (U)
Key: M = maintenance, U = upgrade

I've still got a set of Ultegra brake calipers to go on at some point, and a very light seatpost clamp... beyond that, I've only really got the seatpost to possibly upgrade, but it's already decent(ish) carbon, so it might come down to a question of cost, I guess.

Anyway, as Del once asked, how can it be the same broom? But on the plus side, my bike is unique...