Can you imagine situation in which money supply is fixed, but amount of goods and services would be growing? That could (and most likely would) result in deflation.

You're totally right. Some sort of balanced inflation is needed to encourage people to spend and the economy to spin.

And deflation seem to be worse than high inflation, recession or even staglation

I think it is a bit of a dilemma to pick which one is the worst... They are all so bad for us and for the entire economy. In Syria for example, we've experienced horribly high inflation over the last 10 years. Inflation that kicked goods and services up about 100x! It led most people to stop buying, not because they expect the price of those goods/services to go down, but because they simply no more have enough money to buy

Thanks again for reading and supporting :)