Comment by cesarb

> But there are a lot of git repos out there with commits older than git itself (the Linux kernel itself I'm sure is the most prominent example).

No, the official Linux kernel repository is only as old as git itself (being one of the first three projects using git, the other two being sparse and git itself); the older history of the kernel was deliberately not imported into it. There are later repositories which did import the previous Linux kernel history from Bitkeeper and older tarballs and patches, using mechanisms such as graft to tie together these historical commits and the new ones, but the result has never been part of the main repository.