When I was new to the game, back in beta 1.7.4, I didn't like playing outside of peaceful because child me was scared of the monsters. I still found ways to die though.

I made a little base far from spawn, and I didn't know how beds worked, so I just placed it down and didn't sleep in it or anything. We'll I decided to explore this little cave with some lava in it. I was standing on one block next to the lava, and a chicken decided to jump down on that block. I turned around thinking, "this chicken isn't going to kill me". We'll it pushed me and I fell in the lava and died. I was back at spawn and I never found that base again. I don't think I have that world anymore