Cna yuo raed tihs? Olny 55 plepoe out of 100 can.
I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno’t mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! if you can raed tihs forwrad it.
fi yuo cna raed tihs, yuo hvae a wreid mnid too. Seped rnadieg sluohd be a bezere!
WeirdGuy Creative 
We use something similar in the proofreading training I do to show how hard it can be to find typos when you’re reading for sense instead of letter by letter.
I can read it easily, but I read it much differently than I do when I’m editing professionally. For casual reading, especially online, I find that I don’t even pay attention to every word. I scan lines at a time and only slow down if something in that view catches my attention. At work, though, it’s all word for word with a pen in hand. And I never EVER let my team edit anything they’ve written themselves. The mind fills in the gaps all too easily, especially when you know what something is SUPPOSED to say.
@davisw – yes, just like what Allen said, your mind fills in the gaps if you wrote it. I love thiings like this. Keeping learning and growing!
-eb