It was for a title so there was a goal but it was easily the most tedious thing I've done.
World of Warcraft, specifically during Mists of Pandaria, there's a title from the archaeology profession. You get it by creating a pristine version of every Pandaren and Mogu artifact.
Now for those who haven't played WoW, archaeology works by sending you to one of a few digsites that show up on your map. You go into the area, use the survey command and you'll get a telescope that points in a direction along with a glowing light. The light indicates how close you are. Red is far, yellow is midway, green is real close. When you're on it, you dig it up. Nowadays we have a buff and indicator when you are on the area where you need to dig, but back then it was a bit of guesswork.
You collect fragments that go to your current solve, which is random. And when you have enough you complete it. Normally you get the normal version, but if you're very lucky you'll proc the pristine, a one-time version that you can turn in for some better rewards (a few keystones, which act as bulk-fragements, and a few crates to turn in for other stuff). Its a relatively low chance.
So to get a pristine version, you need:
1. The RNG pick a digsite that you need (there's a third race whose stuff you can dig up but does not count toward the achievement)
2. To be working on a solve that you don't have a pristine for yet.
3. To have a pristine come from the solve.
Unless you are obscenely lucky, it takes you a long while. How long? I forget how long the overall process took me, but, I was 1 pristine solve away from getting the achievement at the end.
And that one pristine? It took me SIX MONTHS of dedicated farming in archaeology to get lucky. Six. Months.
As I said above, the achievement does reward a title, and its a pretty rare one I think as I've only seen like, three other people with it. It is actually my favorite title in the game, and one I display proudly. But when I've been asked about it by others, I like to add that I think I went a little bit insane in the process, because good lord, that was a long grind.
Title, for what its worth, is "(my name), Seeker of Knowledge"