I am guilty of doing this on occassion and overall I am a winning player. I dont use pokertracker/pokeroffice etc. and have been keeping "stats" very crudely for the past few years. essentially all I do is log in a sheet is what limits/site I played on and +/- profit. If I've been running cold, i.e. 3 losing days in a row and I find myself up one decent pot within the first 10 minutes of playing... I have just gotten up and quit for the day. Purely pyschological and many ppl would probably laugh at me for doing so but it seems to work for my mental well being and feels that I've broken out of the rut.