Simple. Soft ball question.
1. Politics. Norway is moving to phase out fossil fuels as a matter of policy. Obviously that will contribute. Policies + targeted social engineering and propaganda.
2. No ties to legacy ICE brands, like GM, Ford, etc.
3. Money: Norway is one of the wealthiest per capita nations on the planet. Money does not factor buying decision making. Wealth also often leads to a desire for impractical/trending consumer goods, and also a certain level of cluelessness or frivolous entitlement. No clue how energy is made or used, little concern for how long durable goods last because they are easily replaceable. Nor any long-term thinking of sustainability, fixability, etc. the things that average people think about, long-term. Rich people don't think "how can I afford this now or later or a replacement."
4. Very congested area. As long as they can move the pollution from the tailpipe to somewhere distant, out of sight and out of mind. They don't see all the pollution in the production and mining, etc.
5. Small geographical area. The entire nation is almost exactly the size of Montana, 148,000 s/m. 650 miles wide, 250 miles tall. So that's basically 1 full EV charge, 2 at the extreme, to get practically anywhere within reason. That makes sense for cars not needing much range.
6. Per capital car ownership in Norway is very high, meaning there are multiple cars per family and ICE vehicles for times when EV won't be practical.