[quirkasaurus]

i don't see any problem with quitting early if you are ahead.

personally, i don't pay much attention to a winning / losing
session, i pay attention to:

if i'm up OR down at a table, and i feel like "i have NO CLUE
how these guys are playing!!" -- i leave.

if i know i'm playing good, up OR down, I stay.

i don't agree that there's "only this one hand" at all.
the longer you sit at a table, the more "meta-game" stuff
should start coming into play, ( seeing betting patterns, etc... )

i HAVE noticed that if i get considerably up at a table and
especially if i've been playing for a while, and i know i'm
getting tired and losing my focus, i do indeed start playing
like a complete moron. as soon as i detect this, i quit.
( may take a few horribly played hands and losses! )

jmtc ( new acronym -- "just my two cents"