I never had this problem when i was younger (and without a job.)
I would play every game from start to finish with almost no interruptions before i moved on to another one.

Now that i can afford all the games i want,it seems to be hard for me to focus on just one game and on top of that i don't have as much time as i used to.So by the time i get back to a game that i was playing 2-3 months ago i have almost forgotten everything.

Lately i'm trying to focus on just one or two games at a time though.