I think the best thing about the GNU Project is it tacitly encourages you to become a better programmer. The documentation invites you to come and play with the rest of the folks who make this software. The code beckons you to take a peek and see what really goes on under the hood.
I've been using this stuff for over 20 years and just gave it a casual "yes, that's important" but for whatever reason this year it's really hitting home. And the reason why sharing that feeling is so important.