The technical details were 'over my head'. [=too complicated for me to understand]
She started to ask a question and then her voice 'tailed off'. [='trailed off']
His handwriting was so bad that we 'couldn't make heads or tails out of' it.
(..) lt might get a little bumpy. Three, two, one, blastoff! You saved us, cowboy. You're our hero. l got a kink in my slink. My tail! Where's my tail? Someone need a hand? -Where's my nose? -Here it is. -Here's your arm. -Give me that. That's mine. (..)2010 Toy Story 3