Whether Aries men can't forget their exes largely depends on their personal emotional depth, how they handle emotions, and the complexity of their relationship with them.
Generally speaking, if Aries men are emotionally invested or if their ex has left a deep impression on them, they may need some time to adapt and let go, but that doesn't mean they will never forget.
However, Aries men are also known for their positive and forward thinking personality. They usually strive to learn from past experiences and quickly step out of the shadows to embrace new lives and relationships. Although Aries men may temporarily reminisce or find it difficult to completely forget, they will eventually let go of the past and continue moving forward.