If you could go back in time and re-invent something, what would it be? But there is a catch!

I thought it could be an interesting topic for the weekend and interesting to see what people would re-invent. However, the catch is that it can't be an expensive product or digital. So no Google, Apple, or Microsoft. You can only re-invite low cost items to buy. For example, I thought about going back and inventing the wooden spoon. Every house has one, they cost very little but if you had the right to the design could be worth billions. It is also such a simple idea that has been around for years, doesn't need to change and is hard to compete with. Interested to hear what yours would be...