You're right. I've lived in Norway and was repeatedly told by Norwegians the country used to be poor, something I believed (there isn't much in Norway that reminds of a wealthy past). Apparently it's just a myth [1][2].
[1] https://www.dnva.no/detskjer/2019/11/en-feiloppfatning-norge...
[2] https://www.aftenposten.no/meninger/kronikk/i/LM1L1/Hvorfor-...