He is so scattered that his room is always messy.
=>He is so scattered that he can't find his keys and wallet now.
但形容人健忘的->forgetful 或 absentminded
She became very forgetful in recent years.(最近幾年她變得非常健忘)
He has a forgettable name.(他的名字很不特別,很容易忘記)
The music makes this movie unforgettable.(這音樂讓人對這電影難以忘懷)