Am I really stupid or is it true love and people make mistakes

25 yrs ago I dated a guy who got very jealous at a party and abused me . I moved on and now 25yrs later I saw him and for some reason I still carry a torch for him and he for me. he is separted, and w/a girlfriend but wants be back in his life and to come there where he is. I have invested a life here but have been uhappy. Can he change or is he all talk. SOOOOOOOOOO confused and thinking about this man over and over and the situation