People who speed up when you’re trying to pass them

I don’t know why but the majority of people on the road are comfortable going exactly the speed limit, most of the time less. But, the moment I decide to speed up to pass them, they speed up as well. Like, I don’t mind being behind you as long as you drive a reasonable speed. And if you’re hogging the left lane, and you’re causing traffic to pile behind you, please move over.