There are so many currencies in the world, with the introduction of crypto-currencies even thousands more than some years ago.
Most currencies are just something humans agreed on to have virtual value, which can help to trade in for real goods instead of trading e.g. chicken against clothes.
But money, as we call some of them, come and go. Most of the time we hope to get more value or money back when trading something.
The only thing which just goes and never comes back is.. time.
Time is also the one thing we do not know how much we have of it. (Except in Justin Timberlake‘s In Time). We also can not put it into a savings account.
So for me, time is the ultimate currency.
Be careful how you spend it!
I’m always reminded on that when I look at my little son.