In what way does the narrator make a distinction between different kinds of time?

In Paragraph 35, the narrator makes an interesting distinction between physical time and "brain time" (35). The narrator says that while the bullet is traveling 900 feet per second at the time of impact, this pace is ridiculously slow when it is compared to the rate at which human thought travels. Therefore, Anders is said to have "plenty of leisure" (35) to contemplate the one memory with which he is presented.