单项选择题

Time and how we experience it have puzzled physicists who have created fascinating theories. But their time is measured by a pendulum (钟摆) and is not psychological time, which leaps with little regard to the clock or calendar. As someone who understood the distinction observed, "When you sit with a girl for two hours, it seems like a minute, but when you sit on hot stove, a minute seems like two hours."
Psychologists have noticed that larger units of time. such as months and years, fly on swifter wings as we age.
They also note that the more time is structured with schedule and appointments, the more rapidly it seems to pass. For example, a day at the beach. Since most of us spend fewer days at the beach and more at the office, an increase in structured time could well be to blame why time seems to speed up as we grow older.
Expectation and familiarity also make time seem to flow more rapidly. Almost all of us have had the experience of driving somewhere we’ve never been before. Surrounded by unfamiliar scenery, with no real notion of when we’ll arrive, we experience the trip as lasting a long time. But the return trip, although exactly as long, seems to take far less time. The novelty of the outward journey has become routine. Thus taking a different route on occasions can often help slow the clock.
When days become as identical as beads(珠子) on a string, they blend together, and even months become a single day. To counter this, try to find ways to interrupt the structure of your day--to stop time, so to speak.
Learning something new is another way to slow the passage of time. One of the reasons the days of our youth seem so full and long is that these are the days of learning and discovery.
The quotation in the first paragraph is used to indicate that ______.