That gist -- after having added to your ~/.gitconfig file as described -- will show a warning message if you have more than 1 stash. That help me to not forgot them and be lost later.

.gitconfig

[alias]
        st = "!git_stash_check; git status"

git_stash_checker.sh

#!/bin/bash
#
# This script display a warning when Git stash contains more that one item
#

GIT_STASH_LIST=`git stash list | wc -l | xargs`
if [[ $GIT_STASH_LIST != "0" && $GIT_STASH_LIST != "1" ]]; then
        echo "WARNING: You have $GIT_STASH_LIST stashes!"
        echo
fi

Obviously you have to put the script in a path included into your $PATH environment variable or put the full path in the .gitconfig file.

Sweet!