Hello! How do you do! 'Tis the crisp notes, plastic in your wallet, and the jingling coins dancing in your pocket, greeting you.   You humans, you obsess over me, you almost worship me; to some of you, I’m the centre of your universe. I’m flattered, but remember there are things I cannot buy, and you will do well to keep that in mind. I cannot buy you good health; even the richest folk cannot escape illness. However, I can buy you healthcare. I cannot buy you friendship, but I can help you maintain friendships. Love, respect, and time are definitely out of my reach.  In my early days, I was a bag of salt or grain. I’ve evolved from the barter system to metal coins to paper and plastic. I lived in leather pouches and chests, but now, besides your wallets, I also live in your phones and computers. You cannot see me or touch me, but you work hard for me. You’re always looking for bargains and looking to spend as little of me as possible. Well, thrift is a...