"Will you still need me ... when I'm 64?" The Beatles.

I've always admired (maybe the better word is envied) those rare individuals who could push the limits of their physical and mental endurance to the breaking point ... and then push it some more.

I even fantasize that I could accomplish some unknown, seemingly impossible feat that would shock the world and etch my name in the history books for all time if I would just set my mind to it and focus. But then reality rears its truthful head, and the dream remains just that. Regardless, I still like to imagine myself paraded through the streets of New York as thousands of admirers shower me with confetti for accomplishing something no one ever thought possible.

As a young boy, I was fascinated with the exploits of Sir Edmund Hillary and his faithful Sherpa companion Tenzing Norgay. I read everything I could get my hands on about the two adventurers' historic climb up Mt. Everest.

It was just over 60 years ago the two intrepid mountaineers set out to do what no man had ever done before: climb the 29,085-foot peak that ranks as the tallest mountain in the world.

While some contend George Mallory was the first to stand on Everest's summit, that could never be verified because Mallory died on the mountain before any documentation could be received that he had actually made it to the top.

And I was completely enthralled by the story of Charles Lindbergh, who became the first man to fly an airplane "solo" across the Atlantic Ocean from the United States to France. The film version of the amazing accomplishment, with Jimmy Stewart as the indomitable Lindbergh, remains one of my favorite adventure movies of all time, and I think I actually cheered out loud when Lindbergh/Stewart saw the lights of Europe and knew he had completed his journey.

The tragic story of Amelia Earhart, who became the first woman to fly solo across the Atlantic but then disappeared in 1937 when she attempted to make a circumnavigational flight of the globe and was never found, is another heroic tale that has garnered my attention for decades. What a courageous/fearless individual she must have been.

There are countless other examples of people who scoffed at the thought of death or personal injury in their quest to boldly go where no man or woman has gone before. A few that come to mind are motorcycle "maniac" Evel Knievel; the great Nik Wallenda, who recently walked across the Little Colorado River Gorge on a two-inch thick cable; the incomparable Harry Houdini, who easily ranks as the No. 1 escape artist of all time; and the amazing Felix Baumgartner, who set a world skydiving record when he jumped from 24 miles above terra firma.

All of these unique people possess(ed) a certain toughness or determination that few, if any, of us can relate to and the mere mention of their names is enough to conjure up images of them and their accomplishments.

But something happened over this past Labor Day weekend that still has me shaking my head in wonder.

For those who were too busy enjoying the final holiday of the summer to notice, American Diana Nyad did something no human being has ever done before when she swam 110 miles from Havana, Cuba, to Key West, Florida, without the aid of a protective cage to fend off sharks.

While some may shrug their shoulders and say "big deal," those folks need to keep in mind that the unstoppable Nyad is 64 years old. I'll write it again just in case you missed it ... Diana Nyad swam for 53 straight hours from Cuba to the United States at the age of 64. Incredible.

As a testament to her perseverance and never-give-up attitude, this was her fifth attempt to complete the historic swim. She tried to do it 36 years ago at the age of 28 and gave it a go three more times in recent years before unfavorable conditions and stinging jellyfish got the best of her and she had to stop.

But not this time. With her lips badly swollen from the sun and salt water, and barely able to stand, Nyad came ashore in Key West Monday afternoon to a cheering throng of ecstatic supporters.

Somehow summoning the strength to speak to her admirers, Nyad told the crowd to "never give up" in life, and, more poignantly, "you're never too old to achieve your dreams."

I'm 63 years old and obviously past my prime, but then again, maybe not. After all, if a 64-year-old woman can find the will to fulfill her seemingly impossible dream, then what's to stop me, or anyone else for that matter, from achieving something I thought was unobtainable?

Thanks for the lesson, Diana, and the inspiration. You rank right up there with the greatest of all time, and nothing will ever change that. Keep dreaming ... for all of us.