I don't make amvs anymore, but back then, what kept me going was having those ideas that constantly made me smile and giggle, thinking how great it would be to make them.
Also, competition was a big factor in making videos seeing how I would fare against my friends and seeing videos on the big screen. I still get chills and excitement watching my videos with a crowd.
I've moved on that passion to filmmaking, but the same concept applies: Thinking of hilariously absurd (or not
) ideas that you're passionate about and bringing them out to a crowd.