When I turned thirty 10 years ago, my wife made me a big party with many friends that included a small concert by the city of Oxford orchestra. It was a beautiful occasion that I ruined by being in a rotten mood. I felt like my existence had crested and then crashed. To me life was a steep arc that rocketed up in your twenties and then went off a cliff in your thirties. The twenties was a time for killer exertion and non-stop energy. Didn't Einstein reach the height of his powers by the time he was 25 and failed to innovate after that? Thirty was for losers. In my twenties I had built a large organization of students at Oxford University where I served as rabbi. I had published several books. I looked upon my youth as a time of limitless vigor and endless promise. But by 30 it was time for Viagra. I was over the hill. An old geezer. To be special meant to do and accomplish things when you are young, not when the grim reaper is fast on your tracks. Now, a week before I turn 40, I look back at who I was then and understand just how immature I was, whatever my achievements. In short, at 30 I was a jerk. I'm tired of being young and foolhardy. Tired of the endless wrestling with the dictates of the ego that is so characteristic of youth. Tired of a life lived with limited prudence and understanding. To be young is to live without wisdom, to lack the benefit both of experience and hindsight. So, I can't wait to turn 40. The Talmud says that when you become 40 you acquire wisdom, and I'm waiting for it to hit me on my birthday like a freight train. Our culture glorifies youth. To be young is to be in the summer of life. To be old is to live in life's winter. First your body turns into jelly and then your faculties into mashed potatoes. BUT KING Solomon, the wisest of all men, described his youth as his winter and his advanced years as his summer. When he was young he lacked wisdom, was bereft of insight. And so he made mistakes. But once he was older, he was armed with the knowledge that comes with experience. He acquired an intelligence and astuteness which only a lived life can bestow. A smart boy became the wisest of all men. Yes, the youth have energy, but also folly. To be young is to be a know-it-all when you don't know much at all. To be young is to believe that you have plenty of time when in reality life is all too short. The young know that the life is fun, while the aged know that life is serious. To grow older is to acquire the humility that comes with having wrestled, having triumphed, having failed, having carried on, and having persevered. So I am thrilled to turn 40. I am tired of the mistakes of my youth, weary of ambling through life with repeated error. Until now I have lived with vitality but in twilight. Now, I can exist with the exuberance that comes with light. TO AGE, in our culture, is to be guilty of a virtual crime, and all too many people, women especially, would just as soon share their deepest character defects before they reveal their age. We adore youth because we place limited value on spirit and maximum value on flesh. Rock-hard abs are preferred to rock-hard principles, a wrinkle-free face to an unblemished conscience. Youth excuses all sin. Teenagers can behave like imbeciles and be excused because they have the one commodity that we are all envious of - eternal adolescence. But the old man who uses a cane, the woman advanced in years who has had hip-replacement surgery, is pitied for their frailty. But what of the fact that they may have no moral frailty? That they don't waste their lives at night clubs, or roaming around shopping malls as slaves to impulse purchases. What of the fact that they can reminisce with friends about something more weighty than the latest James Bond or Borat movie? No matter. They are old. Their only virtue is our pity. We take care of them not because they are valuable but because they are weak. But I vow today, as I enter middle-life and middle-age, that I will not make that mistake. I will not pursue youth, but wisdom, not juvenility but judiciousness, not good times but good sense. My beard is turning gray, and gray it will remain. My hair is still black, but as the salt slowly overcomes the pepper, I'll enjoy being as salty as the sea. I'm a TV host, and image is significant. But wisdom counts for even more. I will not dye my hair but sharpen my intuition. The youth do not need another man or woman to join them. They need someone to guide them. I began professional life at a young age, having received my rabbinic ordination at 21 and become the rabbi at Oxford University at 22. And I used to take a perverse delight in being younger than all my professional colleagues. Now, I'm older than almost everyone I work with. TV is a youthful industry, and I am now the senior citizen on the set of Shalom in the Home. And I'm comfortable with that. But only so long as I'm wiser. I am a Jew, and the time has come to become what my fathers, all the way back to Abraham and Moses have been. It is time to become a sage. The writer's latest book is Parenting with Fire: Lighting Up the Family with Passion and Inspiration.