Had a minor head cold over the last week which meant my ears were slightly blocked, although I didn't realize it at the time. Woke up today feeling great, as if my head has been vacuumed. 

And I just opened up a project I've been simultaneously tracking and mixing over the last few days. OH BOY....talk about brittle....WAY too much top end! It sounds like someone's put an aural exciter at full settings on the master bus. 

Also remember that your nose is very important when it comes to smell as well!
(So, if your music stinks, you may not notice.)
 
HTH.

I'm snot biting!

Pick it, lick it, roll it, flick it!