I'm missing something. I used to use Mercurial and would look at the revision history of the repo with hg log. Simple: all changesets ever made in the repo are shown.
Now I'm using git. I'm pretty excited about learning the new tool, but I'm confused by what I'm seeing with git log. I've done some changes and made some commits. Another person has created a revision and committed as well. I pulled from his repository. I do a git log and his changeset (maybe it's called "commit" in git) isn't in the list. If I explicitly list his hash number (ie, git log <hash>), it shows up at the top. So it is in my repo, but I don't understand how git is deciding to show me what it does when I call git log.
I look at the git help log, but it says in the description that it "shows the commit logs." From my perspective, that's incorrect. Or perhaps incomplete because in reality it shows some subset of them. But I don't know what subset nor how it determines what to show.
Can someone explain git log to me?
Update
btw: One of the first things I had tried was --all, and I see now that many people suggest it. But that doesn't show it either:
$ git log | grep fb2a17c5fb08498e7f2ab364931fddc379be106f
$ git log --all | grep fb2a17c5fb08498e7f2ab364931fddc379be106f
$ git log fb2a17c5fb08498e7f2ab364931fddc379be106f | grep fb2a17c5fb08498e7f2ab364931fddc379be106f
commit fb2a17c5fb08498e7f2ab364931fddc379be106f