Yes, you haven't grokked it. When you work on a development branch like this you can rewrite its history with git rebase --interactive before pushing your commits to the main branch.
You do have to be a bit careful not to introduce broken revisions as a part of your history-rewriting there, of course. Generally if you only use squash (which is sufficient to clean up "sync to laptop"-like changes) it won't be a problem though - it's when you start deleting or reordering commits that interesting things happen.
