Can implicit costs make every option not worth doing?
As correctly pointed out by @Herr K., the opportunity cost of forgoing a movie (bowling) and going bowling (to a movie) is $2.
Hence, the net payoff from going to a movie = benefit - cost = 12 - (10+2) =0.
Similarly, the net payoff from going bowling is 17-(15+2) = 0
Hence the consumer should be indifferent between bowling and going to a movie.