I don't know if it's interesting but here it goes.
I can't spell letter "L". I know the technicque, I know what I'm supposed to do, but when I try I get a bit crooked smile and sound goes sideway. It sounds silly, hard to describe.
When I was smaller I was extremely self conscious about that, and avoided words containing letter "L" (easier in my native language). So, you can guess, I was a slow speaker, can't imagine how many people thought that I'm a bit slow in general.
Now I understand that most people don't pick up on that, but when they do they never hear me the same.