20th century philosopher George Santayana wrote, "Those who cannot remember the past, are condemned to repeat it."
Indeed there is reason in that common sense.
You need look no further than pole vaulter Yelena Isinbayeva for proof.
On Thursday, the Russian great rebounded from the hard times unto which she has fallen to set the 28th world record of her remarkable career, clearing 5.01m/16-5¼ at the XL-Galan Indoor meeting in Stockholm, Sweden. The mark eclipsed by one centimeter the standard she set three years and one week earlier at the Pole Vault Stars Meeting in Donetsk, Ukraine.
Since exhibiting the first signs of failure - I tend to think of them as cyphers of humanity from a world-record cyborg hatched in a Volograd gymnasium - three years ago, Isinbayeva has been written off as a has-been in the what-have-you-done-for-me-lately sport of track and field.
A no height at the 2009 World Championships, a fourth at the 2010 World Indoor Championships, a one-year sabbatical, and a sixth at the 2011 Worlds will do that an athlete.
But hasn't Isinbayeva performed at her best when discounted in the past?
Think back to 2008.
American Jenn Stuczynski (she has since taken her married surname Suhr) shatters the American record at the U.S. Olympic Trials in Eugene, clearing 4.92m/16-1¾. In a post-meet moment of exuberance, she proclaims that she was looking forward to going to Beijing and "kicking some Russian butt."
The comment lit a fire under Isinbayeva, who had been mired in a stagnant period, so to speak, of no world records in three years.
She promptly opened her season at the Golden Gala in Rome with a world-record clearance of 5.03m/16-6, then beat Stuczynski head-to-head at the London Grand Prix, then upped her world record to 5.04m/16-6½ at the Herculis Meeting in Monaco before beating Stuczynski again at the Olympics with another world-record clearance of 5.05m/16-6¾.
"When Stuczynski jumped 4.92m it made me so angry because everyone started to say, 'Isinbayeva is finished, we have a new star'," Isinbayeva told me the day after her world record in Rome. "It made me angry and I am happy for that feeling because I hadn't felt it enough since my last world record."
Flash forward four years to 2012.
This indoor season, an all-important prep period for the Olympic buildup, the pole vault focus has largely ignored Isinbayeva.
Brazil's Fabiana Murer is the reigning world champion.
Suhr, the No. 1 ranked vaulter in the world in 2011, raised her American indoor record to 4.88m/16-0 at the New Balance Indoor Grand Prix in Boston on Feb. 4 and has apparently outgrown the Quonset hut in which she trains in upstate New York.
Holly Bleasdale, the 20-year-old from Great Britain, was hailed as an early Olympic medal hometown hopeful after opening her season with a national-record 4.87m/15-11¾ clearance in France on Jan. 20.
Germany's Silke Spiegelburg set a national record of her own with a 4.77m/15-7¾ clearance in Leverkusen on Jan. 15.
Well, she didn't compete at Sergei Bubka's Pole Vault Stars meeting in Donetsk, Ukraine, site of eight of her 13 world indoor records, and her 4.81m/15-9¼ clearance, modest for an athlete with eight career five-meter clearances, in Lievin last week drew mostly yawns.
Earlier this month I asked Jillian Schwartz, the 2004 U.S. Olympian now competing for Israel, if vaulters sensed there being an opening of opportunity this year given Isinbayeva's recent struggles.
She said, "You never know, but I don't think you could ever count her out."
I'm not suggesting that Isinbayeva lost her medulla oblongata and went all Waterboy, imagining putdowns to get motivated like Adam Sandler's crazed movie character. Nevertheless, you can't help but think that she went to Stockholm feeling undervalued yet undeterred.
Secretly, she knew that her winter training sessions with Yevgeny Trofimov, the early-years coach she has turned to again, had been going splendidly and that she was prepared to show the world that she wasn't finished. More importantly, the pressure was off and she felt like she was "enjoying" vaulting again.
After Bleasdale took the lead with a first-attempt clearance at 4.72m/15-5¾, Isinbayeva entered at that height but needed two attempts to clear. At 4.82m/15-9¾, Isinbayeva turned the tables on her less-experienced competitor and soared over the bar on her first try while Bleasdale failed three times.
With victory sealed and the stage all hers, Isinbayeva proceeded to take the world lead from Suhr with a third-attempt clearance of 4.92m/16-1¾ before setting her new standard on a second attempt.
Afterward, she credited her coach with helping her realize that this was her "real level, not lower." According to EME News, she also spoke of wanting to "jump as high as possible," and jumping "so high the record will stand for a 100 years."
She flashed more of the imperiousness she was infamous for when at the height of her game in an interview with Reuters. When asked if there was anyone else who could beat her this year, Isinbayeva retorted: "I think you can answer that question yourself."
If history has shown us anything, when Isinbayeva is discounted, the answer to that question is a resounding no.