After two or three weeks of work making an animation, for avoinding the Murphy laws you have divided the animation in six parts, rendered each part, joined the uncompressed videos into a big one, added sound to the video, installed all kind of codecs in your pc, compressed the video, and when you play the final result the computer always crashes! One month later I still want to know what is wrong with my computer that is not able to create compressed videos with sound!

Stupidity also evolves!