This Made Me Laugh!

A father received the following letter from his son who was off attending college:

Dear Father,
$chool i$ really great. I am making lot$ of friend$ and $tuding very hard. With all my $tuff, I $imply can not think of anything I need, $o if you would like, you could ju$t $end me a card, a$ I would love to hear from you.
Love,
Your $on.

After receiving his son's letter the father immediately relpied by sending the following letter:

Dear Son,
I kNOw that astroNOmy, ecoNOmics and oceaNOgraphy are eNOugh to keep even an HoNOr student busy. Do NOt forget that the pursuit of kNOwledge is a NOble task, and you can never study eNOugh.
Love,
Your Dad

I hope you smiled!