learning from mistakes

Why is it that we seem to remember more vividly things that we learnt through mistakes (as opposed to say reading from a book)? In a sense this is unfortunate, is it not?

I watched a National Geographic program on rats last night. Research shows that rats are smarter than we think but I still hate them!

The Live Earth concerts took place around the world yesterday. Isn't it funny that concerts aimed at increasing awareness to global warming actually do more harm than good? Just think about all the electricity used to allow the concerts to be staged!

I hope Federer wins his 5th straight Wimbledon title tonight (and equal Borg's record)!