"That says, I can do anything" is the bit that really annoys me.

Yeah, that annoys me too. It is doubly poisonous because it decrees that all failures are due to lack of faith and/or lack of hard work; it doesn't even conceive that some things might simply be impossible for one person to achieve. It is insidiously plausible because the negation of it is true: that one cannot achieve something if one does not first believe that one can. To speak Logic: belief is a Necessary but not Sufficient condition for accomplishment.

Mind you, I do feel frustrated sometimes when people see my craft work and say "Oh, I could never do that!" - because they won't even try.