Preparing to leave a session

[Colts_Fan]

I'll preface this by saying I'm a casual player and really just play for enjoyment. That said, I really value bankroll management and in over three years online I've never had to reload. I primarily play limit games, but my question could apply just as easily for NL players.

Logically (and for simplicity's sake), a player would probably say a session he finishes above break-even is a successful session, and each session leaving at less than that is unsuccessful. For me, the problem I think this has led to is that if I'm preparing to leave a game soon and am close to even, I'll sometimes take an extra chance or two to get above that even mark.

The flip side is that if I'm leaving soon and am above the break-even point, it's almost like "bonus money" and I don't mind taking a chance just for fun. Consequentially, I often end up leaving down a few BBs from where I may have been if I played normally.

Surely the correct thing to do is to strive to play the same whether up or down on a particular session, and each hand should be treated as an independent game for lack of a better word. Unfortunately, that seems to be a hard thought to get through my thick head.

Do any of you come across this problem when you're preparing to leave a session? If this is something you used to contend with and no longer do, what are you doing differently now?