We all like to feel smart and intelligent.  I submit to you that nothing makes you feel dumb like a split seam in your pants or a missing button on your shirt.  With the mini sewing kit, just keep it in your backpack and then when a clothing emergency strikes, excuse yourself to the restroom and quickly stitch up the offending hole or re-attach the offending button.  The needles and threads in the most common colors are ready to go and are pre-threaded.  There are emergency buttons and safety pins as well.

 

This kit is super small and lightweight so you won't even notice you have it until you need it.