You need to realize something. To offer an analogy, if one were to miss an untied shoelace, I hardly think that makes them a poor runner or shoe-wearer. Especially not if they are in a hurry to win a race and that is why they don't notice the errant lace that trips them up when the starter pistol is heard.
This has nothing to do with intelligence at all, and my advice would be to approach the criticism as such, rather than attempting to defend an untenable position. After all, there is hardly a poster in this thread who cannot be linked to the same kind of mistake. Some repeat it daily. Following their example hardly proves anything you would like it to.