There's one thing I didn't understand with Time Squared. If it's the same time-displaced Picard (and shuttle) that are stuck in the loop, how many cycles did they go through? Just one? We see the log where Riker sees the shuttle off, so I assume it was the first one. Otherwise both that Picard and shuttle would age infinitely until the loop is stopped.
Why was that Picard so intent on making the same decision again? How did the real Picard know to fly through the portal? The setup was great, but the payoff was confusing.
Well supposedly what finally stopped the cycle was our Picard killing the time-displaced one. Before that, it would always end with Picard leaving in the shuttle (in order to draw attention away from the Enterprise, or so he hoped), at which point the Enterprise would get destroyed and Picard sent back 6 hours.
This time, Picard realized that the correct decision was to stay on the Enterprise. And since trying to escape
the vortex wasn't working for them, the only alternative was to fly right into the heart of it.
Why that actually worked
, who knows.