"You expected me to grant the letter of your wish in a way that subverted the spirit of your wish or you wouldn't have put 'that works how I expect it to' on the end. I fulfilled your expectations exactly as requested. Having a 10-inch penis on your forehead was exactly the sort of result you expected given how too-good-to-be-true your stumbling onto my lamp was, was it not?"
You getting disappointed in your choice over a while
For example, if your wish is to live forever, genie can grant you that, and you meant to live forever and you will, and only over time you realize you made a hell for yourself.