When a colleague generated a dia graph for each git object that got created when he made a few commits. Understanding the underlying data model was a real aha moment. 13 years later and I’m still grateful for his “mini git course”.

It was when I read the git parable.

I think it might be coming any year now!

It’s only been a decade. Hasn’t happened yet.

sccs, clearcase, rcs, cvs, sure. I’m still deeply in dunning-kruger land for git.

You never reach a phase when you can confidently say that you understand git. But it’s certainly possible to go from “When something goes wrong, I just delete the repo and clone it again” to “Aha! Now I can deal with most of the issues”.

Mine was when I realized that git commands come in two flavors. Those that deal with commits as snapshots (commit, checkout, switch, reset, etc) and those that deal with commits as changes/diffs/deltas (merge, rebase, cherrypick, revert, etc). (Note: This isn’t about how git stores commits on disk). I believe that this is actually the main source of confusion for beginner and intermediate git users.

When I learned about the reflog. I became less afraid of my changes when I knew I could easily recover from my errors. This allowed me to experiment more with git and become more proficient in it.

Another aha moment was learning that an easy way to squash commits is just to do a git reset followed by git commit -am “whatever”

I initially just used it on personal projects just so I could rollback if I needed to. Afterwards I realized that you could branch after watching Fireship videos. I never got an aha moment, but the moment I really understood was after my first pull request to a project I liked at the time.

When I learned that Linus was behind it, otherwise something more straightforward would likely have won the most mindshare.

I don’t think I had a moment like that.

I discovered it, along with other DVCS when it came up, and looked into it and learned it. It was reasonable and intuitive enough for me. As far as I can remember anyway. (I don’t have particular memories of that.)

I feel like I’m yet to have my ahah.

Still haven’t. And I really dislike articles that say stuff like “git doesn’t really store diffs!” followed by a bunch of paragraphs showing they don’t understand what git does store or they are bad at explaining things (or both).

Great. Wow, that explains everything.

Or stuff like “git branches aren’t really branches!” 😑

CC BY-NC-SA 4.0

Every commit lists one or more parents, possibly several parents, like 8 parents. These commits thus form a graph structure.

Branches and labels are just references to commits in this graph structure; they are commit alias, just a name that references a specific commit. Branches and tags are the same, except by convention the CLI will move branches when you commit to a branch, but tags are not moved by the CLI.

(Commits may have many names, they have their commit ID, and they may also be named by a branch or tag. Commit IDs are hashes of the contents of the commit. This ensures, cryptographically, that a commit and it’s ID can never change.)

Git never deletes a commit that is less than 90 days old. If you commit something, rest assured your work is in there somewhere, it’s just that no mortal being may be able to find it. Deleting a branch removes a reference to a commit, but the commits in the branch are still there. The GUI tools usually hide commits that are not part of a branch, but you can see them using “reflog” related commands.