Space Cadet is an off-the-cuff expression, referring to any individual who’s gentle headed, deconcentrated, or has misplaced contact with fact.
People who find themselves billed with this characteristic incessantly have irrational expectancies, and appear too lighthearted and positive when an issue or impediment is gifted.
This is a derogatory expression too, so steer clear of the usage of it in any skilled environments as it may incessantly be won as an insult.