Having lived his life as the gardener on a millionaire's estate, Chance (Peter Sellers) knows of the real world only what he has seen on TV. When his benefactor dies, Chance walks aimlessly into the streets of Washington D.C., where he is struck by a car owned by wealthy Eve Rand (Shirley MacLaine).
Identifying himself, the confused man mutters Chance...gardener, which Eve takes to be Chauncey Gardiner. Eve takes him to her home to convalesce, and because Chance is so well-dressed and well-groomed, and because he speaks in such a cultured tone, everyone in her orbit assumes that Chauncey Gardiner must be a man of profound intelligence.
No matter what he says, it is interpreted as a pearl of wisdom and insight. He rises to the top of Washington society, where his simplistic responses to the most difficult questions (responses usually related to his gardening experience) are highly prized by the town's movers and shakers.
In fact, there is serious consideration given to running Chance as a presidential candidate. Both a modern fable and a political satire, Being There was based on the novel by Jerzy Kosinski and costars Melvyn Douglas, who won a Best Supporting Actor Oscar as Eve's aging power-broker husband.