Not everyone's that lucky genetically. I go to bed at the same and I can get out of bed whenever I want and yet I can't get 7 hours let alone 8 hours. And no I'm not the type who can be refreshed with less than 6 hours of sleep (those are the genetically lucky ones).
Unless all your work involves CSS I doubt it saves 3-4 hours / week. Also, saving 3 hours of work doesn't mean you get paid for 3 hours more. It's also a dependency that's not guaranteed to exist as long as the default browser dev tools or available on every machine.
Recalling yesterday's breakfast is not the same as multiplication table or some other facts you've memorized. Most people don't memorize their breakfast!
edit: as an example, when someone asks "what's your name", do you not recall much faster than what you ate?