teaching dilemna

Once every so often, I dabble a little in the teaching arts...and each experience is a learning one for me. Not just in working with children, I learn quite a lot about myself as well.
Most children are lovely, but today I had two girls in my class who seemed ultra self absorbed, they demanded things from me constantly. They wanted an extra pair of scissors (I caught them cutting their hair with it), they wanted a nicer glue stick...they wanted to take more pictures of their faces, they wanted desperately to be the first to present their project. It really annoyed me, and I felt terrible about this, but I found myself wanting to withhold things from them. I mean, I've been annoying people for years, and it's never gotten ME anything!