Hi BlitzKriegBaron,
Normally you have to determine your odds/outs and one can assume here that you are up against a pocket pair. Question is which one
I see him doing this with 22-JJ like so you can give yourself 6 outs, since you need 3.1:1 and have 2.9:1 you come short so you have to fold
If you do not understand this yet, I recommend you to study the odds/outs article
Best regards,
Gerv