Mission 23, GT4. For those of you who don't know, it was the Skyline race at the Test Course where you had to draft your way to the front. Of course none of you know what I'm talking about, cause chances are if you did attempt this event, you're no longer with us today.
It wasn't that mission 23 was impossible - the Vettel X challenges were much more difficult, as were the S license tests in GT3. It was that it was so deceptive, so evil, it led you to believe you could be successful. With the X trials, you know exactly what you're getting yourself into. You know you likely won't even get bronze, so you temper your expectations. You literally go in expecting nothing.
Not so with mission 23. "It's just the Test Course," you say to yourself. "All I have to do is press X for a couple of laps and leapfrog a couple Skylines, how hard could it be?" Well, assuming your thumb hasn't fallen off halfway through, you might just find yourself in 2nd place with half a lap to go. But, much like an oasis in a desert, victory is an illusion. You'll never catch that Skyline before it crosses the line, but the worst part is you think you can. It's a challenge that lures you in with its simplicity, only to spit you out when you realize there is literally nothing you can do differently to win. At least with other challenges, you can say to yourself "oh, I'll try a different line next time," or "this time I'm braking earlier." But when that task consists of applying ridiculous pressure with your thumb for 6 straight minutes and nothing else, well...good luck.