After I typed that I realized that the whole world could be said to be in oil prosperity still, so the same applies to us all: with less evenly distributed oil prosperity, and not every species of green energy available everywhere.
It wouldn't surprise me if we were at 90% at one point, but at least according to this: https://wdfw.wa.gov/conservation/habitat/planning/energy/hyd..., we're presently only at 75%. Your point still stands - we have a lot of hydro here, and an increasing amount of wind power, especially in Eastern Washington. I went to look into it because I'm always surprised how much of my own (Pacific Power) bill is from coal / non-renewable sources, given that I live within an hour drive to the Columbia and am surrounded by wind farms. I'm told at one point in history (1970s?) Grant county in WA and Umatilla county in Oregon had the cheapest power in the country and were on some kind of 99-year price freeze, all from hydro, but I don't know the specifics.
Not at current levels of consumption and production.
We are about 98% hydro now and it's probably going down as more people use more energy.
But you are still correct, Norway is the ideal country to try this and it is an explicit aim of the government now to have all short haul flights electric by 2050. We already have electric ferries on the fjords, electric buses, and, of course, a lot of electric cars (more than 100 thousand electric cars in Norway now).
Hydro power is an impossible resource to perpetually manufacture more of. The US has heavily tapped out its potential in hydro. First it's difficult/undesirable to manufacture a new source of hydro once you reach saturation, and second it's arguably a terrible idea to do so when you have good alternatives to damming up a natural water flow.
The US is the world's #2 nation in wind energy production and is adding more wind capacity per year than any other nation not named China.
Let's put it into context with the parent's comment you're replying to:
Norway had 1,162 MW of wind capacity in 2017. The US had 89,077. That's a 76 fold gap. However there is only a 63 fold gap in the population size between the two nations.
Given Norway has a meaningfully higher GDP per capita than the US (~15-20% higher typically), it looks even worse when you consider the GDP per capita vs wind energy capacity per capita ratio.
The US exceeds the vast majority of all countries on per capita wind energy capacity, including Japan, Australia, New Zealand, France, South Korea, Italy, Belgium, China, Greece, Turkey, Taiwan, Poland, Mexico, Brazil. Overall the US is doing OK with renewables and keeps getting better by the year. It's obviously important that that trend remain intact.
As for why a country with vast access to hydro would prefer wind energy, Hydro requires large investments, is excruciatingly difficult to upgrade, interferes with local water flow and ecosystems, and in the case that either it is improperly maintained or a major accident occurs, can be very dangerous and deadly.
https://en.wikipedia.org/wiki/Okkupert
The premise is that Norway develops thorium reactor technology and ceases all fossil-fuel production. And then is clandestinely and later openly invaded by Russia, with the blessing of other countries, to seize oil and gas production facilities and forcibly re-open them.
The what now?
You mean more bonkers than letting EDF and the Chinese do it?
E.g. Uber