Poker is a game of skill, but it's a long-term skill game. Variance however can spike at any time for any of us. Just like you can run really bad, you can run really really good and win well above your competency level... but only in the short term.
The same thing happens with the WSOP ME. It's not just a "prestige" thing -- pros consider it one of the softest fields with one of the biggest paydays in poker, which is why most pros makes an effort to play it. Yet every year amateurs go deep. Remember Darvin Moon from a few years ago? He was a likable enough guy, but damn was he a terrible player. A backwoods lumberjack who was put in by his local pub league. And yet he made it HU and won millions. Jamie Gold, anyone? ME bracelet winner and winner of the single biggest ME payday in history. Also widely considered the fish at most high-stakes games. Jerry Yang? Another ME bracelet winner that hadn't done anything in poker before or since his win. Even droolers can run insanely hot and go deep.
I can even point to myself here: My first big score in poker was taking a FTP $25K Guaranteed several years ago. I think it had like 1300+ runners, took 7.5 hours to finish, and paid out like $7500 for 1st. I was only a couple years into playing online and was nowhere near the player I am today. I don't think I was a total fish by that time, but I still have the HHs from that game and a couple years back I reviewed them in a replayer. Damn did I cringe at some of the plays I made.