I have been working with git for just over a month. Indeed I have used reset for the first time only yesterday, but the soft reset still doesn\'t make much sense to me.
You can use git reset --soft to change the version you want to have as parent for the changes you have in your index and working tree. The cases where this is useful are rare. Sometimes you might decide that the changes you have in your working tree should belong onto a different branch. Or you can use this as a simple way to collapse several commits into one (similar to squash/fold).
See this answer by VonC for a practical example: Squash the first two commits in Git?