Do you log your workouts?
I do log my workouts. I use an academic calendar planner from an office supply store (because my training schedule more closely resembles the school calendars). Each day I write down the warm up I did, the workout and the times or distances I ran. I note how I felt (although I only do this if the workout was really bad). I do the same for weight workouts except if I feel a lift was too easy or too difficult I add a note to make an adjustment to the weight for the next time.