Dr. Allenby (Richard A. Dysart) manages to trace the actual identity of "Chauncey Gardiner" (Peter Sellers) when he finds the business card of the lawyers who told Chance the gardener he had to leave his old home after his benefactor died. The two men are at the side of Benjamin Rand (Melvyn Douglas) when he dies, and afterward Allenby refers to Chance by his real name and he responds. Though Allenby could reveal the truth to the world, he doesn't - he's too amazed by Chance's total innocence. Chance/Chauncey will become (by implication) the new husband to Ben's wife Eve (Shirley MacLaine) whom he does in fact love; he knows that, but not yet that he is to become a presidential candidate as per Ben's last wishes.
At the funeral, Chance loses interest in the proceedings and wanders away, alone. In the final shot, Chance is so enjoying the peace of the woods and lake that he *actually walks upon the surface of the water* without initially realizing it. When he does, he accepts it as just one of those things and continues his stroll.