I was out walking with my 4-year-old daughter. She picked up something off the ground and started to put it in her mouth. I took the item away from her and I asked her not to do that. 'Why?' my daughter asked.

'Because it's been on the ground, you don't know where it's been, it's dirty, and probably has germs,' I replied.

At this point, my daughter looked at me with total admiration and asked, 'Mumma, how do you know all this stuff? You are so smart.'

I was thinking quickly. 'All mums know this stuff. It's on the Mum Test.

You have to know it, or they don't let you be a Mum.'

We walked along in silence for 2 or 3 minutes, but she was evidently pondering this new information. 'OHHH...I get it!' she beamed. 'So if you don't pass the test, you have to be the dad.'

'Exactly,' I replied with a big smile on my face.