I also find this approach is often the kind of thing that
  leads people to assume they cannot do something; they think
  that only "really smart" people can possibly do some
  particular thing, and refuse to try as a result. Of course,
  it can also go the other way--because someone does
  something hard, they insist that they must be really smart,
  or else they couldn't have done it. This only reinforces
  the problem.

To be fair though, this isn't exactly a problem - it's ensured you've gotten a whole lot of lucrative work because there's not a whole lot of competition ;-) There are, possibly, contrasting areas I feel able to tackle that would initially intimidate you (as video compression intimidates me) - that's what makes specialization such a great thing.