First played the demo at around Beta 1.9. I built a basic wooden house for like 2 days. Then I put lava next to it and everything burned up. I then bought it around the minecraft 1.0 Release. I was scared of monsters and didn't want to go out at night. I didn't know about anything called "peaceful mode". I played for quite some time without knowing A LOT of things. Then at around 1.2.5, all my friends started playing.
It was really fun, we experimented with redstone, block physics, made theories...
And now, I'm all alone again. All of them stopped playing more than a year ago and started playing GTA and COD and LOL/DOTA instead. [I personally do play GTA V daily though]
Oh, I almost forgot.
I started playing because my cousin showed me the 1.7 Beta version at his house. What made me check it out myself was the dynamic day and night cycles I think... And the fact that the game was almost infinite.
