Have you ever made a major reading error?

I mistook the society for the retired, and semi-retired Edmonton, for society for the retarded and semi-retarded. I asked the office while walking by the sign how could they have semi-retarded?

After a few laughs the seniors directed me to the front desk and had me ask the question again. I was 17.

Did you ever make a big mistake in reading something?

Humor welcome.