My biggest takeaway is this: You can tell a story which challenges readers to have to think… to actually work to stay up with the plot, time jumps and the like… if at the core of the story you have a strong emotional touchstone.
Love… lost love… the pain of lost love… the confusion of being in a relationship… memories… each and every emotional aspect of Eternal Sunshine of the Spotless Mind is universal. We’ve ALL had those interpersonal and intrapersonal experiences, the highs and the lows. Because of that, we stay with the story as we want to find out what happens to Joel and Clementine.
This goes for all stories, of course, how we need to create some avenue for the reader or audience to identify with key characters, and especially the Protagonist. But with a complex narrative, it’s even more critical.