“Be kind to strangers” is the sort of thing your mum drills into you growing up.

Not just because it’s a Nice Thing To Do, but also because you don’t know what others are going through.

People have bad days - personal struggles, break-ups, bereavements - all the time and we simply don’t know it.

You can’t tell anything at surface level, so it’s better to give those around you the benefit of the doubt.

This approach extends to random acts of kindness too, and is the reason why an everyday gesture went viral recently.

When Mackenzie Mauller brought the woman in the queue behind her a coffee earlier this month, she didn’t think much of it.

But it turned out that the two women lived close to each other in Uniontown, Ohio - and Mauller later received a note through her mailbox:

This small act of kindness went viral - for a very important reason