ah, so

they set you up, and then they knock you down (Charlie Brown and the football, another recurring metaphor.)

They 'set you up' because, what the hey, you're a kid! Cool, look, she's learning to walk! Wow, look at her go!

But then, a minute later: Too fast! She's learning too fast! She's going to be too much for us - quick, trip her up! Put something in her way, distract her! Don't let her get too good at this or she'll be insufferable! No one will be able to live with an ego that size!

So she seizes up: Should she stay or should she go? (yes, song lyrics.) Paralysis. Which way is safe? Which will win the approval of the parent, that lovely smile that makes her so happy to see, like winning some prize? She doesn't know, she simply can't guess. The danger is too great, better not try. Better to avert her gaze, not look into the eyes of this one-minute-beaming, next-minute-harsh person who appears to have control over her life.

So she stops connecting with them, these people who are like the white-coated researchers in some lab making rodents push levers to receive random and unpredictable rewards.

She disconnects, isolates, because the unpredictability is too scary, the potential for pain too great. Instead, that being who was so bright and full of life only a moment ago, dims, shuts down. Her light diminishes to a dull glow barely visible except in the darkest of rooms where it can't possibly be objectionable to anyone.