What's the most accidentally ignorant thing you've ever said/done? I'll start...

I found my best friend from 2nd grade on Facebook, awesome! I immediately go on his timeline and ask how he's been after 10 years. Not paying attention to anything else. About three hours later I go back on facebook and see a post from him, or so I thought was him. The post basically said, "Hey, this is Andrew's father! Today was a very bad day as we found the cancer has spread. It was hard news and he's relying on your prayers to get him through. I keep my laptop here at all times and he's been reading all your messages and wall posts, please continue it helps him fight!" TL;DR I asked an old friend how he's been to find he might die from cancer