Before and After bathroom tile

Did you know you are supposed to seal you tiles and grout? 
Hmm....  I didn't.  That was a hard lesson to learn. 
Here is my lesson:  White grout gets dirty.  Octagon tiles are charming until you have to clean the tiny grout around them individually.  If you seal your tile apperiantly it is supposed to stay clean!
We spent DAYS scratching away the top layer of grout, bleaching, cleaning, sealing.  If you are attacking a similar tile I would highly recommend spending $100 on a dremel to remove the grout.  It is worth your time and money.

It is nice having a brand new clean white floor!  :)  We applied two layers of sealant, and from what I hear (oh how I love Young House Love!) sealant should be reapplied every 6 months. 
Have you ever learned a home related lesson the hard way?  (If so, could you clue me in?  I'm not such a fan of learning the hard way!  lol...)