scatterbrained
From Longman Dictionary of Contemporary Englishscatterbrainedscat‧ter‧brained /ˈskætəbreɪnd $ -tər-/ adjective informal FORGETnot thinking in a practical way, so that you cannot do things or you forget or lose things —scatterbrain noun [countable]Examples from the Corpusscatterbrained• The years of being branded impulsive, scatterbrained, too idealistic rushed back to mock her.