Oh my, the gear I've gone through over the years ...

lament for sold gear
in approximate order:
* EF-S 18-55 (the original) - SOLD
* Tamron 70-300 (the 2004 version) - SOLD
* Sigma 10mm fisheye - SOLD
* 28-135 - SOLD and good riddance
* 24-70L - SOLD (I miss it)
* Nifty Fifty - SOLD (and then later purchased another)
* 135 Soft Focus - SOLD (outclassed by the 135L, although not to shabby itself)
* 70-300 DO - SOLD and never looked back
* EF 20mm - SOLD and not missed
* 70-200 f4L IS - SOLD because it's ostentatious
* 180L - SOLD because it weight a thousand pounds
* 85 f/1.8 - SOLD and slightly missed
* 28 f/1.8 - SOLD because it halates
* 50 f/1.4 - SOLD for greener pastures
* EF-S 18-135 - still got it! although I'll probably sell it soon
* EF 35-70 - SOLD because I don't know why I even bought this ancient thing
* 200 f/2.8L - SOLD in lieu of 135L
* 35 f/2 - SOLD and I sort of miss it
* 100 macro - SOLD and not missed
* Zeiss 2/50 - my baby <3
* 100 f/2 - SOLD and not missed
* 24L - on its way out the door
* 135L - still hanging on!
* Zeiss 18 - RETURNED within the 30 days (I'm learning!)
* Nifty fifty - not going to sell it this time
* 16-35L - on it's way here right now!
* 24-105L - will probably get this in a couple weeks
This list does not include rented or borrowed gear, which is also lengthy. I don't know why I've worked my way through half the Canon lens catalog over the years -- I mean, I know in my head that it's the photographer that makes the picture and NOT the gear. But for some reason I always feel limited by what I've got, and that if I just sell lens X to finance lens Y then I'll finally have the right gear for my shooting style.
On the flip side, I actually feel like my shooting style has evolved greatly over the years, and I've been good enough about selling what I no longer need that the gear I have tends to match my style at the time. I spent a long time in primes learning how to shoot and what works well at specific focal lengths, but now I'm coming back around to zooms just so I can have less stuff and focus more on composition and less on gear.