You don't have to touch a floppy disk to cause damage to it. Floppy disks store information by magnetizing information onto them. Certain devices such as televisions and phones can send off magnetic signals of their own, possibly altering or destroying the information that's been saved to the disk.
Time is another factor that can play a part in whether a floppy disk is effective.
After all, they're not designed for long-term storage. It's a good idea to store the floppies that you do value in a storage container that was built specifically to carry the disks.