Prior to Aberdeen on Tuesday, the last time any club took three points from them in the championship was on April 28 when Motherwell won 3-1 at Fir Park.
For players who had an unbeaten season and more clean-sheet records in their sights, it's like climbing up a ladder only to land on the wrong square and slide all the way down a snake.
However, Lennon does not think they will have to throw a double six to get going again.
The much-publicised incentives have gone, but there is still the chance to set a new points record.
To better the 103 collected by Martin O'Neill's side in season 2001-02, the current crop can't afford to lose even one of their remaining 11 games.
But, given the fact of their record this season, they know they have it in their locker to achieve this.
Other firsts still available to rekindle Lennon's hurting Bhoys include the fewest goals conceded in a season.
That currently stands at 18, set by Celtic in that same, impressive 2001-02 title- winning season.
Even after shipping two at Pittodrie, they have four to spare.
Most wins in a season is also in their sights. They are on 23, and must win every game in the run-in to better that mark by one.
Achieving that would also see them equal the lowest number of defeats in a campaign.
That currently stands at one, and, you guessed, it, was set in 2001-02.
Lennon has already emphasised he wants his team to get the job done as quickly as possible, in terms of clinching their third title in a row.
The record for that, since the SPL then the SPFL was established, is April 6, set in 2006 at the end of Gordon Strachan's first season.
With six games before then, Celtic have an excellent chance of beating that.
But whenever the flag day does arrive, Lennon does not want their season to end there.
The hard work put into getting them to where they stand today, 21 points clear and requiring just 13 more to become champions, will not be allowed to be undermined.
That means standards must be maintained all the way to the final day on May 11.
After analysing what went wrong at Pittodrie, Lennon is confident there was enough fight shown in defeat to give him reason to believe his players still have the willingness to keep their form going.
He said: "We haven't had many of those kind of tests of their mentality this season.
"That's probably why I enjoyed the game more than any others that have gone before.
"It was a real test for us, and I got what I wanted out of it -apart from the result."
Lennon is convinced that, after coming to terms with the disappointment of finally seeing his shut-out record ended by Jonny Hayes' wonder strike, Fraser Forster will be leading the way in terms of starting all over again against Inverness on Saturday.
The manager said: "It's incredible what he has done this season, and that must not simply be forgotten just because that run is now over.
"He was beaten by a wonder goal at Aberdeen, and you have got to congratulate Hayes because it was a tremendous hit."
What turned out to be the winning goal, a stooping header from Adam Rooney as he stole in between Charlie Mulgrew and Efe Ambrose, was not so admired by Lennon.
"I was disappointed by that goal," he said, having passed the same message on to his players. "We should have defended that better."
Having lost Virgil van Dijk after just 12 minutes of action, the influence and organisation the Dutchman brings to the defence was clearly severely missed.
His red card will now rule him out of this weekend's game against Inverness.
But it is all part of the education 22-year-old Van Dijk is rapidly absorbing.
And Lennon predicts there is much more to come from the £2.6million signing from Groningen.
"Virgil is what you want in the modern-day centre-half," said the man who brought him to the club last summer.
"He's big, has great timing in the air, and technically he is proficient with both feet.
"Virgil has got good pace and he reads the game very well. He has surpassed our expectations."
Now Van Dijk's suspension can act as a well-earned rest after playing in 37 games for his new club this season.
And Lennon is sure he will take this hit in his usual relaxed manner.
"It's his temperament we like," said the manager.
"When you sign a player, you don't really know what they are going to be like behind the scenes. But Virgil has a fantastic attitude."
The best measure of how well Van Dijk has settled in is that, while strikers always grab the headlines and the attention, he is a firm favourite to be in the running for the Player of the Year in his debut season.
But perhaps an even more ringing endorsement of his impact is that the concerns expressed when Celtic lost homesick Kelvin Wilson as the summer transfer window was about to close have quickly been forgotten.
Lennon conceded: "We felt it might take a bit of time to replace him, but Virgil has been a very good fit."