foolish

adjective3

1. •
   (of a person) often making silly choices because they do not think carefully

   • His wife and the neighbours lamented over his strange conduct, his dullness and melancholy, and began to think that he was grown foolish. — 1828
2. •
   Not based on good sense or judgement; as a fool would do or conclude.
3. •
   Resembling or characteristic of a fool.