People who live in the spirit of carpe diem try to get the most out of each moment of every day, without worrying about the future.
The Latin phrase carpe diem, which is usually translated as "seize the day," literally means "pluck the day (while it's ripe)," from a root meaning "harvest." You can use it to encourage your nervous friend to join you on a roller coaster: "Come on, carpe diem!" And if you can't stop fretting about what might happen next week or next year, just try to adopt your own carpe diem philosophy — getting all that you can out of today.