Now, now, you don't have to feel sorry for yourself.
I can tell why you're not able in noticing any grammatical errors.
That's because you're not determined to do so. But I am.
When I write a bug report, I include my findings of grammatical errors and glitches.
Most people tend to only post glitches, and not grammatical mistakes.
Well, since I'm a grammar corrector, I do both.