1. Inflation: you will have 10 at the value of the currency in 2022, not 2021
2. Negative savings rates:
> There are fears that negative lending rates, which are expected to lower borrowing costs for households and businesses, would force high street banks and building societies to offer negative savings rates.
If you put it in your bank account you will lose some of it. The idea is that the bank is paying you to hold the money because otherwise it would have to pay the central bank more than that to hold (some of) it - or at least, that's how I understand it.