What do you think putting more money into circulation does to demand & nominal purchasing power?
An excess of money causes increased demand per unit dollar and subsequently, higher prices and inflation, through mechanisms including the Cantillon effect, changes in monetary velocity etc.
If i deposit more $ in your bank account, what happens to your nominal demand?
Ideally people would save for a rainy day. But people don't, and can't, always do this. Because for some this is the rainy day.
Non-ideally I would assume that most demand increases would go for non-groceries, and non-commodities in general, such as housing and travel, though I would expect some increase in durable goods commodity prices as people replace older goods with newer. Yet here we have grocery price increases. Are salaries in the grocery production chain going up 18%? I doubt it. The price increases are coming from elsewhere.