Ive done lots of stupid things over the years, tiling bathrooms etc/ and forgetting to measure out the height of the bath and then when it comes to fitting theres a cut of about half an inch to the bath lol
Floated a window wall the other day, it was well pissed and also had a curve in it top to bottom, so I thought, **** levelling it out as theres a limit to how much Im going to level something, bricky should have atleast TRIED to build a wall correctly that day! anyway, set me beads up, made sure there was enough play so that when I got to the bottom of the wall it didnt run to nothing (had that before on another curved to **** wall), anyway got spreading, by time I got to the bottom the right hand side was about half an inch further out than the left, thus to close to the right hand rad pipe! so ****** if the guy is ever gonna get a skirt behind it again! unless he moves the rad pipe! all cos me right hand bead was slightly more angled than me left, what a ****, if I levelled them up it wouldnt have been an issue, but then Id have had about 2inches of gear on the top of the wall, no way hosay!
Anyway Ill try think of some proper bad ones, got plenty from when I was starting out but there expected! I wanna hear ones from us as "experienced" tradesman, some of the stuff I do I really do think to meself I gotta be the only **** out there doing it Lol

and dont get me started on me clumsy side, Captain splash I think Im called now, ******* buckets of water :X