And yet, in real life people do try to spend their entire budget rather than risk getting it cut. For example, federal agencies spend an average of 4.9 times more in the last week of their fiscal year than in a typical week during the rest of the year. (Citation: https://www.nber.org/papers/w19481 )

Budget is power and status; there's no reward for returning unspent money to the company.

Depending on why the sink needs repairing, it might cost $50 to repair, or it might cost $100 to repair. If you give me $100, and I repair the sink and return the $50 I didn't spend, and you punish me for this by saying from now on I can never have more than $50 for repairing the sink, you give me a strong incentive to waste money on future jobs instead of returning it.

Parent: "What do you want to order?"

Child: "I don't know..."

Waiter: "An excellent choice."

The first thing to do is to make sure this is actually true. Mental associations have a big effect on taste - see those experiments where 'experts' are fooled into thinking white wine with red dye in it is red wine, or cheap wine in an expensive bottle is good wine.

So, do a blind taste test, and see if you can still tell them apart.

'Energy loss' has little meaning unless you were trying to do something with that energy.

A useful context would be in something like a car engine. Some of the energy from the fuel is lost via (for example) heat escaping from the cylinders and the engine, instead of propelling the car.

So if you were burning food to heat the room, light would be lost energy. If you were burning food to light the room, heat would be lost energy.

But if you were burning food for no particular reason (beyond 'experiment') the question is pretty meaningless, unless the intended answer is something along the lines of, 'energy is never lost to the universe, it just changes form'.

https://www.mentalfloss.com/article/66523/how-do-anthills-survive-rain

"The ant fortresses you find on your lawn have a number of defenses. The first is the anthill that sits right on top of the nest. The mounds are usually made with special kinds of dirt or sand that absorbs water and dries quickly. Water hitting the convex dirt tends to bead and run off the side.
Some colonies, like mangrove ants, will send a soldier ant to plug up the entrance hole with its head. This living stopper prevents rain from entering but is only a temporary fix, as it blocks gas exchange with the surrounding area outside the anthill.
When heavy rain leads to water entering the tunnel, it usually doesn’t go far. Ants tend to burrow at least a foot underground and have an intricate system of tunnels that work like storm drains. As long as the rainfall isn’t too heavy, the water will pass through the nest without pooling.
With some clever tunneling, ants can trap air in various chambers throughout the nest, and entrances to chambers come from below, preventing water from coming in. "

"Evidence suggests beavers don’t build dams because they enjoy it, but because running water precipitates the influx of potential predators in their environments."

Those things aren't mutually exclusive. Is there really evidence beavers don't enjoy building dams? Because that sounds like saying, "Humans don't eat because they enjoy it, they eat because they need food to survive." When in fact we eat because we enjoy it, and we enjoy it because any people who didn't like eating would have died out.

Note that without the magnetoreception, this leads to fairly haphazard navigation. Can't follow the stars on a cloudy night. Still, if you're just trying to head somewhere warm rather than a specific area, it's good enough.