When playing Minecraft (v1.0.0) and you make yourself a portal to the Nether to harvest some yummy looking new NetherStone for your house, REMEMBER WHERE YOU LEFT YOUR FIRST PORTAL. Cause building another DOES NOT WORK.
No. You end up where? THOUSANDS OF BLOCKS AWAY FROM HOME. And when you try to fly home anyway, it takes forever no matter how fast you fly and after about two thousand blocks your computer grinds to a terrible halt and chokes on the rendering. And then you have to replace your game with a previously saved copy. Butthead.