the first one wasnt my own error but the mechanic's at the bike shop i took my s**** to.

i got a new wheel that came with a ****ty cog and lockring, but i wanted to use my old ones because they were much better quality. i didnt have a lockring tool at the time so i tried to pop the lockring off with a hammer and a flathead screwdriver. that was kinda dumb, so i took both wheels to the mechanic and said, here, switch these cogs out for me. so he takes it and says ok. and i go browse the shop for maybe five minutes, and i come back and he is standing there at the counter struggling with something. i go over and hes trying to get the lockring off. turning it the wrong way. and i come up to him and ask him if hes sure he knows what hes doing, and he looks at it for a second, and then says oh yeah, its the other way isnt it?
at that point i was just like ok, im not taking my eyes off this idiot. 4 minutes later, he comes over to me. excuse me sir but it seems that ive stripped your cog. and not the ****ty aluminum one either. the 50 dollar bank buster cog i bought because it was the only one available at the time that i had learned to appreciate. if anything he should have replaced it free of charge. nope.
needless to say i was just a bit ticked off.

and then one time i replaced the stem on my brothers bike for him and forgot to tighten the bolts down just the top cap, and the next time we went out for a ride, he and i raced down to the traffic light at the end of our street and as he attempted to trackstand at the red his handlebars turned in the opposite direction of his wheel. the look he gave me was one id never seen before, fear, confusion, anger and relief, all rolled into one. i love my brother and would never want him to crash on his bike, but i dont think he believed me.