Fully live in each chapter of life.
Don't try to live your chapter as if it were a different one. Here is one illustration of the principle. It is very important for young people to pursue wonderful things in life while they're single - starting a ministry, picking up an instrument, learning a trade, traveling the world, enjoying a large number of relationships, and that kind of stuff. The problem occurs when these folks try to continue living as a single person after they are married, not understanding that work, hobbies, relationships, and ministry involvement that were appropriate and healthy as a single person can be unhealthy and downright sinful as a married person. The bottom line is this: Strive to cultivate contentment in every chapter of life, and enjoy each one to the fullest, because you may never live in them again.