Help me remember where this is from?

For a project I’m working on I’m trying to find a reference to a description of heaven that made an impression in the recesses of my brain, but I’m having trouble pinning down its source. The gist is that heaven is described as perpetually existing in one moment from your life in which you were truly content. I think this is from a scene in a movie in which…I think possibly a Native American character…possibly an ex-convict?…was explaining this to someone else…I am not sure. Those clues might lead you astray, but the gist is what I really remember. I think also I might be confusing this with the Tralfamadorians description of a pseudo-afterlife from Slaughterhouse-Five, but I could be wrong there too. 

In conclusion, can you help me?