I totally relate to this problem! I've found two solutions for dealing with it. The first, only buy basic sketchbooks. I still buy Moleskine ones, but they are the ones with natural covers and thin, crappy paper you can get in three packs. That doesn't really help with your situation. The second solution: The first thing I do when I start a new sketchbook is write a strange arbitrary name right on the cover. My current sketchbook is "That Guy From That Thing." Some past sketchbooks have been "Loch Ness Lawyer" and "Don't Touch My Neck." For some reason random titles get rid of my expectations and I don't feel intimidated. Wow, this comment is way too long.
You name your sketchbooks? AWESOME. And as weird as that is, it's a good idea. I usually like getting those cheap Clairefontaine spiral books, but this sketchbook is supernice; it's hardcover and has got a supercool illustration on the front done by some designer...which makes me feel like I'm competing with the cover. So yes. Good idea! Long reply to long comment!