I spent a few days digging a really big hole in the ground in Minecraft once. I just turned a small island into a massive square hole in the ground. It was deep, wide and went all the way down to bedrock. This was before we had creative mode, so I had to make a wooden pickaxe, then mine stone to make a stone pickaxe, use it to mine iron, then mine some coal to smelt the iron into ingots and use them to forge an iron pickaxe. I then mined down until I found enough diamond to craft a diamond pickaxe and reach bedrock level.
There was no productive reason to dig a massive hole in the ground. I guess I just did it because I could. I got a lot of resources and materials out of it, though, so I guess that was kind of cool. This was also before the hunger bar, or I would have starved to death several times over during this glorious fool's errand.