Text Area

I have finished the text area, and you can use the test_area app to test
it out.  One question, currently when you are on the top line and you
press up, the cursor moves to the beginning of the text.  Also, if you
are on the bottom line and move down, it moves to the end of the text. 
I know most text editors don't have this "feature."  What do you think,
should I take it out or leave it in?
Thanks, Chris