<s>[INST] What's the difference between those two? Why has full self-driving in particular been so hard to predict? [/INST] I mean, the thing that really got me, and I think it's going to get a lot of other people, is that there are just so many false dawns with self-driving, where you think you've got the problem, have a handle on the problem, and then it, no, turns out you just hit a ceiling. Because if you were to plot the progress, the progress looks like a log curve. So it's like a series of log curves. So most people don't know what a log curve is, I suppose. </s>