When The Stranger and The Dark Wizard’s paths finally cross, it's confirmed that they know each other from before all of this. It’s well known that Saruman was the first wizard to arrive in Middle-earth. Then this line seemingly alluded to the fact that in Rings of Power, this magical being was also the first of the five wizards to land there:

Season 2 of "Rings of Power" ended up being even worse than the first season, from how it portrayed Sauron to nonsensical orc motives.