Crypto coins
Bitcoin, Litecoin, Dogecoin, Ethereum, uPlexa... blockchain, hashes, mining, pools... they all made my head spin when I first heard about them.
I am a very curious person, and during last year I started to have a closer look at crypto currencies. I managed to setup a mine and successfully mined Monero and other coins. By successfully I mean I managed to setup a mine and it worked, not that I got rich by mining crypto :-)
In my opinion, crypto is here to stay, and one must keep up with technology.