If you want to know why you kept working, slogging for the thirty days, the most effective way is to see what you are doing with the paycheck. What you are doing with the paycheck will very loudly demonstrate why you kept working the thirty days. See what you do with the fruits of your labor.
Or maybe it is not merely salary that you get; we consume psychic things as well. Maybe on the thirtieth day, your boss comes and praises you in front of the entire staff, and that really inflates you within. If it inflates you within, then you are consuming the praise, aren’t you? And that will tell you why you kept working the thirty days.
See what is it that you do with what you get out of your action.