forgetful in WordNet English dictionary

1. (of memory) deficient in retentiveness or range
   "a short memory"
   unretentive  forgetful  short 
   
2. not mindful or attentive
   "while thus unmindful of his steps he stumbled"- G.B.Shaw
   unmindful  forgetful  mindless 
   
3. failing to keep in mind
   "forgetful of her responsibilities"; "oblivious old age"
   forgetful  oblivious