He is in that landing pattern that middle-aged heartthrobs finally come to: time for home and family and a woman who is worthy of keeping his love. The 50-plus Oscar winner, producer and political activist George Clooney is apparently engaged to be married. He's at a particularly pivotal age. Forget about the 50s being the new 40s -- the 50s are really very specific. Even the most youthful people will start thinking about the meaning of life as the years no longer stretch out in a fantasy of infinity. Those years between 50 and 60 do seem to be a particularly poignant age for men, especially the kind of man who has trouble giving up motorcycles. Sometime in this period, the thrill seekers and lust lovers get their whiff of mortality -LRB- perhaps because of their latest motorcycle accident -RRB- and they turn to love with a new sense of its gravitas. With a nod to the motivation most of us mortals have, they are ready for an emotional legacy. -LRB- Hint: watch for children -RRB- It might irk Clooney to be seen as so predictable. He's a gifted, idiosyncratic, goes-his-own-way, irreverent kind of guy. But he has been practicing for this life transition in full view. In his films, he has played lost middle-aged men, lost in their careers, lost in neglected marriages, lost because of a lack of connection to something important -- Up in the Air, The Descendents, Michael Clayton,