Thrown Rock

Evidently, two spaces after a period to end a sentence is the wrong way to do it. Today is the first time I've heard why, but it's only the second time I've heard of it being a problem. I'm 49 years old, learned how to type on a manual typewriter in the spring of 1978, and didn't use computers to do much typing until 1987. Admittedly, two spaces after a period on the computer screen often looks weird, but is it really something to get your panties in a wad about? Aren't there more important things to get upset about?