I know you should have no regrets, but I wish I had stopped and thought at the time. In no particular order, I have chucked out the following,
1 Holdsworth Professional frame as I loaned the forks out and never got them back
2. Raleigh 653 Race frame because I dented the top tube
3. Royce chainset and rings because I broke the left crank
4. Campag large flange on Mavic Pro sprints because I stopped using 5 speed (it was late 80s)
5. 1st generation Dura Ace rear mech because I broke the cable clamp
6. about 6 pairs of leather racing shoes when I went clipless
7. all my wool jerseys when I got into lycra
8. my almost knee length Bernard Hinault overshoes (remember them) when they went out of fashion
9. two pairs campag record pedals when I went clipless
10. my brooks B17 saddle because it was "too heavy"
Can anyone beat that for embarrassment value ?