Steve Howe Interview: Something strange

There was an interview with Steve Howe posted here a short while back that contained a passage that I can't really fathom, and I'd like to hear your opinions about it.

As an aside he mentioned that he couldn't read or write sheet music and he memorizes all his material. Now to me that's just weird.

Here is a world famous guitarist who, for some reason, can't or won't learn the basics of his trade. In heaven's name, why? It's not rocket science and he's had about 40 years to learn it from when his career really took off. Surely it would have made life so much easier for him. It's just basic, and any kid learning an instrument like the piano can master it in a relatively short time.

I could possibly understand it  if you're a musician who only plans to stay in the game for a limited amount of time, but in SH's case, somewhere along the line of the last 4 decades it must have struck him that he'd be doing it for a while longer. Even if he should be self-taught, why not make the effort after a while? Is there such a thing as musical dyslexia? Is it just laziness?

I imagine SH's probably not the only one, but he's one of the most prominent musicians, so can anyone cast any light here? I'm baffled.