git stash is given the UX of a stack, but it's more a list or a set of commits. The commits in your git stash don't need to be related (their commit parent pointers can point at very different branches). At some point if you are heavily using lots of stashes you tend to switch to referring to them by commit message and/or stash number instead of thinking it a stack you build bottom to top and always and only pop from the top.