I have to thank artist John Coombs for this fascinating example of how the mind works: 

If you read the next paragraph quickly you’ll see how much we see and how much we recognise.

I cdnuolt blveiee taht I cluod aulacity uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid. It deosn’t mttaer in waht oredr the ltteers in a word are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.