In case your question wasn't rhetorical, here are some possible explanations:
- Because they're children. It's their job to not listen.
- Because they think they know what you're going to say.
- They listen, they just don't want to obey.
- Their learning style has a non-preference in the listening department.
If that's the case, you can still get your children to pay more attention when you're talking - you just have to make sure a few of their other learning style preferences are satisfied. Perhaps your child will listen better in a more informal environment or at a different time of day? Perhaps they'll respond better in a warmer room or if they're allowed to nibble on pieces of fruit?
What are your child's listening preferences? Find out here.