It's my life mission and creed to go to ANY concert without spoilers on the setlist.
Should have gone to concerts before the 00's!
It's not THAT hard, even though with superstar bands such as Iron Maiden it's quite difficult.
Even so, to make an example, I still haven't the slightest clue about what Metallica is playing currently, and I intend to keep that up until I'll see them in early May. With Iron Maiden I remember I had to unfollow their Instagram page but aside from that, unless friends don't post videos on FB and you avoid of course the official forums, it's relatively easy to not know a setlist.
With DT themselves I managed to fully avoid info on the last tour and I didn't even have to stop posting here, I just avoided the tour section.