Somehow I do not think that Barack Obama gets up in the morning, brushes his teeth, looks in the mirror and says, "Wow! A fresh face!" It doesn't happen at 45. At 45, you count the crow's feet and measure the circles under your eyes.

If you are a woman, you start reading the fine print on the Oil of Olay Regenerist label. After, of course, putting on your new reading glasses. If you're a man, you start swiping eye cream from your wife's stash.

While you are inspecting your not-so-fresh face, you remember that when Mozart was your age he'd been dead 10 years. Albert Einstein published the big theory of relativity at 36. Thomas Jefferson wrote the Declaration of Independence at 33. It begins to occur to you that you will never be a prodigy or the youngest anything, not even the youngest president of the United States. Teddy Roosevelt had that sewed up at 42.

I say this to add a dose of reality to the chatter about the man slated to announce his candidacy for president on Feb. 10. Obama is indeed this year's designated "fresh face." But on the flip side, those who are not questioning whether the Illinois senator is too black to be president are asking whether he is too green.

That's not green as in tree-hugging. That's green as in inexperienced and/or young. Even his little daughter once asked, "Are you going to try to be president? Shouldn't you be the vice president first?"

The last time age was a presidential issue, you may recall, was when Ronald Reagan was running against Walter Mondale. The 73-year-old Reagan quipped, "I am not going to exploit for political purposes my opponent's youth and inexperience." Obama has his own retort ready for anyone who asks about his political resume: "Dick Cheney and Donald Rumsfeld have an awful lot of experience."

But I find it bewildering to hear so many Americans worrying that a man who is middle-aged, by any demographic measure, might be too young. The question — "how green is Obama?" — may say less about the senator's youth than the country's age. Or the baby boomers aging.

In 1960, the average age of Americans was 29. Today it's 36 and climbing. In 1960, the life expectancy was 69. Now it's 77. More to the point, the baby-boomer generation that is forever setting the agenda has begun turning 60.

Most of the green-talk is indeed from boomers, a generation that was just coming of age — teenage — when Jack Kennedy was killed at 46. Is it possible that the same generation that famously didn't trust anybody over 30 when they were 20 doesn't trust anybody under 50 now that they are turning 60?

One of the charms of the boomers, the watermelon in the demographic python, is how they are managing to age without getting old. My favorite factoid comes from a Yankelovich study showing that boomers define "old age" as starting three years after the average American is dead. It's a new wrinkle on the 1965 song by The Who: "I hope I die before I get old."

But the side effect of feeling forever young is that boomers may regard their juniors as perennially too young. It's seen in the generational lament about the adult children who can't get launched. It's also seen in the boomers' defense of their (primary) place in the pecking order.

Remember, the average age of the Senate is 62. That's when you round out 89-year-old Robert Byrd and 42-year-old John Sununu. If the Senate is clogged with incumbents, consider the Ivy League. The Harvard faculty has more tenured professors over 60 than under 50. Then, too, scientists once got their first major research grant from NIH at 37; now the average age is 42. Sorry, Einstein.

Obama was technically born at the tail end of the boom, but places himself politically outside the "psychodrama of the baby-boom generation" which he describes as "a tale rooted in old grudges and revenge plots hatched on a handful of college campuses long ago." The "new generation" of network anchors leading the green-talk — Brian, 47; Katie, 50; and Charles, 63 — are all older.

Well, it's a shock when the people you went to high school with start ruling the world. It's another rite of passage to acknowledge juniors as your superiors. But boomers are now turning 60 with a life expectancy of 82. It's an early sign of memory loss to forget that at 45 you were wise or foolish, or both — but you weren't young.

That master of the last word, Oscar Wilde, said, "Experience is the name everyone gives to their mistakes." He figured that out at 39.

Ellen Goodman is a columnist for The Boston Globe. Reach her at ellengoodman@globe.com.