He has really fixed ideas about things. He either really likes something or dislikes it, and makes his decision based on that.
ーHe has really fixed ideas about things. He either really likes something or dislikes it, and makes his decision based on that.
「彼は思い込みが激しくて、好きか嫌いで判断する」
例：
I have a friend who has strong preconceived ideas about things. He's not a bad person, but it can be troublesome being friends with him. He either really likes something or dislikes it, and makes his decision based on that. He has the opposite personality from myself.
「私には思い込みの激しい友達がいる。彼は悪い人ではないけど、仲良くすると面倒くさいことがある。彼は好きか嫌いかで判断して、私とは正反対のタイプです」
ご参考まで！
カナダ 
