What?

Sometimes my elder son amazes me, Yesterday morning was the usual rush to get everyone ready for school & work, when we eventually got into the car, my eldest son, who had obviously sussed I was a tad stressed, said.
Mum,
''Yesterday was History, Tomorrow's a mystery, today is a gift,that's why they call it the present,''
In his own little way he was telling me to chill and enjoy the day. And do you know what that thought stayed with me all day, and yes I did have a relaxed day.