Father Dougal McGuire is a character in the comedy series Father Ted, played by the actor Ardal O'Hanlon. Renowned for sleeping in his Irish national football team shirt, Father Dougal is one of life's innocents. He quite cheerfully admits that "the lights are on but no one's home".
Need to find some examples of Dougal's devastating insights to illustrate this...
For example, Dougal and Ted visit a tourist attraction and see a map poster with the legend "You Are Here". Dougal exclaims "Wow! How did they know that?"
In another scene Ted compares some toy cows with the real cows in a nearby field: "Now, let's try it again, Dougal: these are small, but those are far away. Small...far away. Small...far away." Dougal shakes his head in amiable incomprehension.
Ted: "Dougal, I have some good news."
Dougal: "You're getting married!?"
Ted: (pause) "You were joking there, weren't you?"
Dougal: "Er, yes."
(You may remember that Catholic priests are required to practice celibacy.)