Enjoy the pleasures or opportunities of the moment without concern about the future.
Example:
He was convinced he would die young, so he told himself "carpe diem" and lived an adventurous life.
Carpe diem comes from Latin, where it literally means "Pluck the day," though it is usually translated as "Seize the day." A free translation might be "Enjoy yourself while you have the chance." Some people make carpe diem a kind of slogan for their lives, feeling that life is too short to spend it worrying about the future, and that we should grab the opportunities life gives us because they may not come again.