[mtogo]

You wouldn't expect a carpenter to say "I can both screw and unscrew screws from wood".

Given that a huge number of professional programmers can't do the programming equivelant of screwing and unscrewing screws, that actually does make a difference.

[StavrosK]

True though that may be, I don't think the OP's intention is to convince us that he's less than utterly incompetent...