Resetting activities each day
I figured that on a new day your old quests would sort of be temporarily forgetten, and that the website would prompt you saying '3 quests yet to be completed'.
Instead, the site remembers that I already completed 7 quests a few days ago, and it has a big friendly tick. This gives me the impression that I did something already, and I don't need to bother doing anything.
This has been fixed!
Aaron Winborn commented
I agree, especially considering that the quests appear in the to do block, along with power ups and battles, which have a different behavior.