[TPIN] What IS competent?

[trumpeterdave at comcast.net]

Mike Vax said:

"Any change or addition of another mouthpiece, especially for a 
young person, should be done with the help of a competent teacher and not just 
because somebody on a list like this says so."

Ah, there's the rub: "competent"

Who/How defines "competent" ? 

I have been struggling for about 9 months with 
selecting a mp for lead playing.  My teacher  is a fabulous player, and, more 
importantly, a tremendous teacher--a 
serious student of trumpet playing. (He is a Gary Radke disciple) BUT-I just 
flat out didn't like the mp he set me with. (A GR)
I  could not get air through air through it.
I gave it a 2 month committed tryout. Played ONLY the GR. Didn't even THINK 
about
going back.  Until it occurred to me--"Just for kicks, I will try my old 1C just 
once..."
Voila, I was back in business blowing freely again.  (Still looking for a little 
help with the high range, though!)

So the moral of the story is, well, I don't know what the moral of the story is.  
Whatever works? Listen to yourself? Don't worry about it? Try everyting in sight?