Lt. Dan Taylor: Forrest, I never thanked you for savin’ my life.
Forrest Gump: He never actually said so, but I think he made his peace with God.
When Forrest needs to tell you something about Lt. Dan, you listen. Lt. Dan is a hard guy to impress throughout the entire movie and Forrest genuinely respects him. He respects him so much he even saves his life in Vietnam.
You would think after a harsh wrath of verbal abuse and crude aggression from the lieutenant, over many years, that Forrest would never speak to him again but that is what makes this relationship so special, you know they care for each other like family. Lt. Dan has a unique way of thanking people and this scene/quote certainly expresses that.