Grammar Police

I've been caught and detained by the Grammar Police.

Today, Erin and I attended a Press Release workshop and I learned that it's correct to use only one space after a period. Who knew? Certainly not me! Also I learned that using exclamation points is not good...I can't believe it! And last but not least, I learned that there should only be one comma in this sentence: the red, yellow and green hats were for sale.  I would have put a comma after yellow but apparently that is called 'The Oxford Comma' and it's seen as 'snooty' and 'uppity.'

This is shocking, scary, and outrageous.  I'll stand for none of it!