Maybe this will help. I actually tried this out on a class once and they got it eventually. Suppose suddenly, every dollar in every pocket and bank account in the land suddenly became 10. What would happen? Well, there are no more goods than there were before, so merchants will raise all prices by a factor of 10 and we would be in exactly the same position as before. The reverse actually happened in France in 1960 or so when they knocked two decimal places off all currency and 100 Fr notes became 1 Fr notes and so on. No real difference except that had to reintroduce centimes for old francs.
Now let me vary my experiment by dividing the population in half and leaving the money in the pockets of one half unchanged and multiplying by 20 all the money in the pockets of the other half. The total money supply under the two scenarios is approximately the same and the prices would willy-nilly rise by a factor of ten, but suddenly half the people would see their material wealth rise by a factor of 2 and the other half would be impoverished. (Actually, my numbers don’t quite add up, but the principle is valid.) What has really happened is that nearly all the true wealth of half the population has been transferred to the other half. And this, with somewhat different numbers, is what happened in Spain. The people who acquired all that gold became wealth, but everyone else, along with the Spanish economy, was impoverished.
Now you may argue, with certain validity, that if the government simply printed a trillion dollars and paid off all its debt, the money would effectively be transferred from the people who owed the money to those to whom it was owed. I cannot refute that and I suspect it might be true. Trouble is, it would still make the economy tank, most likely. Just think back to the eariy 1980s when I got a CD that paid 20% interest for 5 years (not, however, reinvested at that rate). Of course, with taxes and inflation I was actually getting negative interest.