A possible concise summary is:
Jeffy gets a new car from his parents after they receive a $10,000 check from an insurance company. He spray paints the car and drives with the top down. He gets beheaded by a power line that was hanging too low on the road. The doctor tries to transplant his brain into a seal's body, but fails. He then uses a time machine to go back in time and stop Jeffy from getting beheaded. He also kills his past self to avoid having two of him.
Some possible key facts extracted from the text are:
1. Jeffy got a new car as a gift from his parents.
2. Jeffy spray painted his car and drove it with the top down.
3. Jeffy was beheaded by a power line that was hanging too low on the road.
4. The doctor tried to save Jeffy's brain and put it in a new body.
5. The doctor chose Cecilia the seal's body as a donor, but Jeffy's brain died.
6. The doctor used an Apple watch time machine to go back in time and stop Jeffy from being beheaded.
7. The doctor also killed his past self with a robot clone and went to Applebee's with Simmons.