DH was walking in the woods and a tree/big branch had fallen across the path, wedging against another tree.
He bent down to go under it, but didn't quite bend down far enough and caught his head on the branches as he went under (turned out it was full of thorns which cut his head - this is relevant!). It hurt like hell and bled but didn't think much of it at the time.
Three weeks later, his cut had turned into a massive painful lump. After pinning him down talking him around, he let me have a poke.
There was a scab there that I picked off. I gave the lump a squeeze and POP, out came an explosion of puss, and it kept coming and coming.
After all the puss drained out, there was still a hard lump. I squeezed it further and a massive, and I mean bloody huge, thorn came out 
It left a bloody huge hole in DHs head. Literally, a big circular, perfect hole.
I took bloody loads of photos while dribbling with joy It was years ago, I'll have to dig them out one day.