He counts toothpicks. He spilled a box of toothpicks on the floor. He took one look at them and he knew exactly how many there were. He counted them in seconds.
11 seconds sound clip from the Rain Man (1988) movie soundboard.
You can hear this line at 01:01:48 in the Blu-ray version of the movie.
Quote context
[...]
- Nothing, just kidding, it's an inside joke.
- Out of curiosity, does he have any special abilities?
- Well, he's got a pretty good memory.
- I read about this. I want to try something here.
[...]