One thing about git I learned the hard way is the use of diffs and patches (more accurately, 3-way merges) for operations like merging, cherry picking and rebasing. Pro-git (correctly) emphasizes the snapshot storage model of git - it helps a lot in understanding many of its operations and quirks. But the snapshot model can cause confusion in the case of the aforementioned operations - especially rebasing.

For example, I couldn't understand why the deletion/dropping of a commit during a rebase caused changes to all subsequent commits. After all, I only asked for a snapshot to be dropped. I didn't ask for the subsequent snapshots to be modified.

Eventually, I figured out that it was operating on diffs, not snapshots (though storage was still exclusively based on snapshots). The correction on that mental model allowed me to finally understand rebasing. (I did learn later that they were 3-way merges, but that didn't affect the conclusions).

That assumption was eventually corroborated somewhere in Pro-Git or the man pages. But I couldn't find those lines again when I searched it a second time. I feel that these operations can be better understood if the diff/patch nature of those operations are emphasized a bit more. My experience on training people in rebasing also supports this.

PS: Thanks for the book! It's a fantastic example of what software documentation should look like.