One of the first things we learn as kids is that it's important to wash our hands.
Handwashing helps prevent disease spread. It can keep an office running instead of shutting it down due to a viral illness.
It's especially important to wash your hands if you are interacting with newborn children or potentially vulnerable elderly adults.
But we don't always appreciate the reason why handwashing is so important: we touch a shocking number of filthy surfaces every single day.
Here are some of the most surprisingly dirty things we come into contact with on a regular basis.