1.To fail utterly at everything in life. (referenced to Yamcha failing at everything in the anime series Dragonball Z)
2. To have a brief successful start, followed by non-stop fail
3. To build up expectations, only to have them dashed against a stone by constant fail.
4. No matter what you do, you fail.
5. When your best attack is the Wolf Fang Fist.
6. When you peak at the beginning of life.
I was the valedictorian in high school, but i totally Yamcha'd when I got to college.
Kel Mitchell (from Kenan and Kel) totally Yamcha'd his acting career.
The day I was born was the best day of my life. After that, I just Yamcha'd