Smiles brought to you by the letter "U"

We have been working on letters a lot with Artichoke in preparation for kindergarten.  And when I say a lot, I really mean all.the.time.  We sing songs about letters.  We play with letter flash cards.  We watch movies about letters.  We draw the letters.  We spell anything and everything there is to spell.  
 
But somehow, there are some letters that just haven't been sticking.  There seems to be no rhyme or reason to what is sticking and what isn't.  But regardless, we are going to continue this letter madness until we get all 26 52 of them.  Does any other parent hate lowercase?  Just when you thought you were getting somewhere then you start again!
 
This morning Artichoke spelled Rudy.  R-U-D-Y
 
I can't begin to explain what a big deal this is.  It is only four letters, but it includes "U". A letter that has yet to be properly identified.  There might have been an impromptu celebration complete with high fives and a little dancing!