I'll tell you what makes me furious: Insecure women who accuse every male around them of "mansplaining" when they are wrong.
A friend of mine has had numerous precancerous cells removed from his skin. He's interested in using much more sunscreen now. One of his friends, a woman who is a licensed esthetician, claimed that SPF factors in sunscreen tell you "how long it lasts". She also recommended a broad-spectrum sunscreen.
I do not want my friend listening to her half-assed advice and getting cancer. So I said that she was correct in advocating a broad-spectrum sunscreen. I said that SPF does not indicate "how long the sunscreen lasts"; sunscreen does not break down in sunlight. Rather, SPF is a rating system that explains what percentage of UVA rays the sunscreen will block. Moreover, I said, sunscreen should be applied at least 15 minutes before exposure to the sun (in order to allow it to soak into the skin), should be reapplied no matter what every two hours, and if a person is sweating or has been swimming should be applied every hour.
She accused my correction as (a) mansplaining, and (b) a copy-and-paste job from some Web site.
I'll tell you what also makes me furious: Insecure people who can't put five words together in a sentence, and who accuse me of copying and pasting simply because I take the time to (a) be informed, and (b) write well.