When time is short, you get more out of it, be it work or pleasure. We call this the focus dividend—the positive outcome of scarcity capturing the mind.
The focus dividend—heightened productivity when facing a deadline or the accuracy advantage of the blueberry poor—comes from our core mechanism: scarcity captures the mind. The word capture here is essential: this happens unavoidably and beyond our control. Scarcity allows us to do something we could not do easily on our own.
Focus is a positive: scarcity focuses us on what seems, at that moment, to matter most. Tunneling is not: scarcity leads us to tunnel and neglect other, possibly more important, things.
This is a basic feature of the mind: focusing on one thing inhibits competing concepts. Inhibition is what happens when you are angry with someone, and it is harder to remember their good traits: the focus on the annoying traits inhibits positive memories.