How about going to the grocery store on day 1, when you have tons of motivation, and buying EVERYTHING you can possibly eat in a two week period that's primal. Then refuse to go back to the store during those two weeks, even if you run out of something "important". Grok couldn't go to the store...he had to make do with what he had.
Don't plan the meals if that's not your thing...just don't let yourself eat anything that's not in your primal stash.
The difference between your child analogy and this eating thing is that you're not a child! You're an adult, capable of independent learning and independent self-motivation if you trust yourself enough.
Zone diet on and off for several years....worked, but too much focus on exact meal composition
Primal since July 2010...skinniest I've ever been and the least stressed about food