From wikipedia, on the 1994 referendum:
"After a long period of heated debate, the "no" side won with 52.2 per cent of the vote, on a turnout of 88.6 per cent.".
This, to me, looks like it could relatively easily have gone the other way. Two or three TV debates going differently, have one of the better debaters for the No side get the flu at the wrong time, have the Yes side be more eloquent, have one leading No campaigner say/do something people get upset about a week before the vote, etc.
Maybe it doesn't really change people's minds, but does lower turn out of No voters?
If Norway joins in 1995 along with Sweden, Finland, and Austria, what then? What changes with how the EU works? Will the € be created the same? Will Norway affect that process so that Scandinavia joins the € from the start? That's about a 10% increase in €-zone GDP, could affect it's prevalence outside the official eurozone or how the analogue of the 2008 crisis is handled.