In movie and television universes where Santa exists but parents don’t believe, the question is often raised “Are parents surprised when their children find presents the parents didn’t buy?”
The answer to this is disturbing. Santa is a magical entity; when he delivers presents to children, he also delivers false memories to parents at the same time. Parents who did not buy that bicycle or dollhouse suddenly remember having done so - with all the associated memories of long lines and laborious assembly. In the Santa-verses, the most fortunate adults are those few who still believe (like Iggy’s father in the Year without a Santa Claus); they can be secure in their memories. Everyone else is unknowingly living a lie.
If the parents couldn’t afford the gift, do the altered memories include the source of the money? Are bank records altered? If the “source” is a bonus from work, are the company’s internal and bank records altered? Co-workers’ memories? Tax records with state and Fed. governments?
Santa isn’t so much a person but a form of intoxication caused by the combination of pine resin and burning yule log. It has a stronger affect on kids because of their low body mass. They’ll start to recover weeks later with fading memories of the cool puppets and space helmet left under the tree when it was really just socks and underwear.
Throw in some eggnog and they’ll start seeing elves.