Lights turn out after a few minutes (except maybe when you manually turn them on.)
ACC turns off after about 30 minutes. And I think the overhead / post door buttons also turn off after a few minutes.
Check the individual lights that can be forced on by switches -- but those are tiny drains. My grown up kids used to leave them on which I would not realize until I drove the van at night.
Make sure nothing is plugged into the "battery" sockets (the ones that show a battery on the cover) -- those remain on regardless of the ignition switch status. Things like chargers, etc. draw small currents even if not actively charging.
I would go back to the van about 15 minutes after you leave it with the door open (without the fob) and see what it is on and what is not (without opening any doors.) It should be completely dark.
And as mentioned above and on various threads, if it happens again, make sure you get the battery load tested. Premature battery failure, although relatively rare, is mentioned regularly.
2017 Pacifica Touring L Plus
Build date Oct 2016 - Delivered 11/30/16