simple minded

/ˈsɪmpəl ˈmaɪndɪd/
adjective
  1. Having a simple or unsophisticated way of thinking; not complex or clever.
    • Don't be so simple-minded as to believe every advertisement you see.
    • The villain in the movie was simple-minded and easily tricked.
    • His simple-minded approach to problems often missed important details.
  2. Kind and innocent, without malice or cunning.
    • His simple-minded honesty was refreshing in a world full of lies.
    • She was simple-minded in the best way, always trusting others and seeing the good in people.
    • The old man had a simple-minded kindness that made everyone feel welcome.