Hitler's Minecraft Pun

Okay, so you really don't get this, do you? You're probably more focused on finding where you put your keys this morning. Anyway, the joke is a pun. In the video game Minecraft, players collect resources by digging, which is called 'mining'. The punchline 'Mien' sounds like 'mine' but it's a reference to 'Mein Kampf', which was a famous book written by Hitler. So, instead of saying 'I'm mining', it's a play on his book title. It’s based on history, which you clearly need to read up on. Now go, a bear has things to do.