As they enter retirement age, baby boomers are once again at the center of the attention of marketers and industry.

I speak from experience. Hardly a day passes by on which I don’t receive a letter, brochure or magazine in the mail, inviting me to go on a trip to far-flung places, continue my adult education, or join a community of like-minded, active seniors.

Aging has never been so much fun and so full of promise, it seems. Take, for example, the movie “The Best Exotic Marigold Hotel,” which turned out to be one of the longest-running box office hits this year. In it, a group of retirees from England goes off to India (of all places) to start a new life that appears to be easier and more enjoyable than everything they’ve left behind. There is affordable health care, cheap housing, and, surprisingly enough, even job opportunities open up for those who have the courage to seek them. Some things may be a little chaotic, but that’s all part of the fun when you no longer need to stress over small stuff.

Unlike for its forbearers, retirement for this generation – so we are told – is a new beginning rather than a move closer to the end.

The defining word now is “adventure,” which, of course, comes from the Latin term for “arrival.” Instead of fading away, this is the time to (finally) come into one’s own.This unprecedented optimism about the prospects of old age is also big business.

Just look at the self-help industry that thrives on people’s willingness to change their lives and start over again and again. Instead of the twilight zone, the later stages in life are now called the “Power Years” (to quote one title among countless best-selling books on the subject), a time to break with traditional roles and an opportunity for reinvention and creativity.

“Due to longer life spans, economic uncertainty, and the mass rejection of yesterday’s model of old age, yesterday’s model of retirement is being transformed,” wrote the two lifestyle gurus and bestselling authors of “Power Years” (Wiley, 2005), Ken Dychtwald and Daniel J. Kadlec.

“Instead of viewing the years ahead as a time of decline, retreat, and withdrawal, we are coming to see this as a terrific new opportunity to reevaluate our lives, consider new options, and chart new courses. The next chapter in our life’s journey can be one of personal reinvention, financial liberation, career innovation, new relationships, and social and spiritual fulfillment.”

The authors suggest that the new retirees should consider themselves as “ageless explorers” who travel the world, start businesses and live life to the fullest at every moment they have left. Americans are especially receptive for messages like these. The idea that our best days are always ahead of us is an important part of our fabric, both individually and as a nation.

But is all this actually achievable or just wishful thinking? A much different, one might say, pessimistic, take on aging comes from Susan Jacoby, author of “Never Say Die – The Myth and Marketing of the New Old Age” (VintageBooks, 2011). Jacoby agrees that baby boomers have many advantages that were unheard of in the past.

“Many old people today – if they are in sound financial shape, if they are in reasonably good health, and if they possess functioning brains – can explore an array of possibilities that did not exist even a generation ago.” However, she continues, “at some point, nearly every baby boomer will have to cope with the shattering of vanity and self-delusion about the capacity to remain, as the song goes, forever young.”

To be sure, there is nothing wrong with trying one’s utmost to stay physically fit, mentally sharp, socially engaged and curious about the world.

But we must also remain realistic about our natural limitations. More importantly, we must be aware that our aging process starts at birth. While this may sound a bit dramatic, it is undoubtedly true that taking care of our well-being is equally important at every stage in life.

The healthier we eat and the more we exercise, the better in shape we are, the better we can deal with life’s challenges, the more intact we come out at the other end. Life is what you make it, as the saying goes.

So, let’s not wait until it’s almost too late, let’s make life as good as it can be right now.