We all come across locks that kick our hindquarters from time to time. Except for fgarci03 - he always gets the lock open.

Some locks are just not pickable by conventional means. Examples would be most Abloy locks, EVVA MCS, and so forth. The rest take practice, time, practice, patience, practice, learning, practice, and finally practice. A bit more practice wouldn't hurt, either.
Anything in the Master lineup is certainly pickable. They are not a mid to high end lock like Lockwood, Mul-T-Lock, Medeco or ASSA. Even those high end locks can be picked with a fair bit of... you guessed it... practice.
Take the lock cylinder apart, and only put pins and springs into one chamber, reassemble, and pick it until you feel confident with the lock. Then add another pin stack and pick that until confident. Then the next stack, and the next, until you have the lock fully pinned. We refer to this as 'progressive pinning'. The best part is that it works! That is how I learned Medeco. Yes, even those can be picked.
Don't give up! Try our advise. We'd love to see you stick with it and learn.
Best of luck,
Gordon
Just when you finally think you have learned it all, that is when you learn that you don't know anything yet.