Time Flies?

1. Time flies when you're having fun. We can also say that if time is dragging, you're not having fun.

2. By Einstein's theory of relativity, time slows down as your speed approaches the speed of light.

3. From 1 and 2, traveling at the speed of light is probably not fun at all.

4. But as a general matter, the feeling of acceleration to a high rate of speed (as in an automobile) can be at least somewhat thrilling, i.e., fun.

5. Therefore, if acceleration can be fun at relatively low speeds, but (from 3) is less fun as you approach the speed of light, the curve depicting the relation between fun and speed is probably non-linear.

6. Why would this be the case?