What keeps me motivated... that is a long one...
1. Training... beating or reaching a goal. It could be maintaining a 19 MPH average, maintaining a 90 RPM cadence, climbing a hill in a certain time, reaching a certain number of miles, etc.
2. Enjoying the time thinking of nothing but me, my bike and the scenery (or lack of it)
3. Knowing that every pedal stroke I take makes it closer to beating my number one problem right now.
4. Knowing that there is a nice ice cream sandwhich waiting for me back home.
5. Knowing that for just a few hours I am free.
Now what motivates me to go out and absolutly pound the crap out of my legs again and again on a steep hill interval... beats me... I guess I am just insane!

Sometimes it just takes a minute to focus before going to tackle it one more time!