Back a long time ago I used to work as a Data Entry Clerk for a large gas firm based in Britain, ...it was mind numbing work, with targets to reach that constantly put pressure on you to perform quickly but without ruining your quality level.
After several years I was done and the day I quit & just walked out was fantastic. Literally didn't even know I was going to do it, went into work, got stressed and pi**ed off in the morning & just quit.
Has led me on to better things and happier employment in every job since.