When I sign with other deaf programmers, we don't have trouble communicating with signs, even about technical programming.

When I go to the doctor's office and someone interprets for me, I don't have trouble understanding the doctor.

Please don't speak so assuredly about things you clearly don't understand. https://en.wikipedia.org/wiki/Sign_language

I agree with the 1st sentence however. You don't have to know sign language to be content or happy with your life, even if you are deaf.