I have been using Git a long, long time. I have worked on Git clients and libraries. At some places I've worked, I am the person folks go to when they need Git help.
And yet, only today I learned you can pass -m to commit twice (or more) and it will do the right thing of making each successive message a new paragraph (which is useful for the convention of a short summary as a single first line and following paragraphs as a more detailed message).
@halfogre Same - worked a bit with git, and since learning it at uni, at every job since, I got rep of "git magician" for some reason. And while I am impostor-syndromeing about it, I learned recently a fun and useful thing about it:
Instead of push ... --force or -f you can also just use +branch-name in the command to convey that you want to force-push to remote branch with the same name. I'm still not using it often, but it's easier to write when I do it. 
Drew Miller
Hazardius 🡗🡗🡗 🏳️🌈🏳️⚧️