The Parkhead side went into their Champions League dead rubber at the Nou Camp on the back of a thrilling 7-0 Scottish Cup victory over Hearts at Tynecastle and an emphatic 5-0 Scottish Premiership win at Motherwell.
However, the Hoops were hammered 6-1 in Catalonia to end their doomed European campaign on a sobering note but they quickly shrugged off the trauma to win the four remaining league games in the month without losing a goal to keep them on course to retain their title.
Ahead of the home league game against Motherwell on Saturday, where Celtic will look to extend their unbeaten run in the league to 21 games, the Northern Irishman was asked about the most pleasing aspect of his award.
"Probably the reaction from the Barcelona game where we obviously came off the back of a heavy defeat," he said.
"The character the team showed more or less straight away was great.
"We kept our clean sheet record intact and we were winning games.
"We carried that on into the New Year with a fantastic (4-0) result against St Mirren so the way they lifted themselves and galvanised themselves after what was a disappointing night (was pleasing)."
Celtic went to Turkey for a winter break earlier this month following the convincing win in Paisley where the club played two games in the Antalya Cup.
Lennon was pleased to be able to see some of his fringe players in action as others who have featured regularly this season were given some time off.
"It was very worthwhile in terms of some of the fringe players getting some games and the boys who have played the majority of the games getting some time to rest," said the former Celtic skipper.
"Nir Biton, Teemu Pukki, Amido Balde got some game time and (Derk) Boerrigter, after having injury problems, got plenty of game time in the two games.
"I think they got a shot of confidence from that and that is exactly what we were looking for.
"So what we have is those four pushing for a place which makes competition in the squad healthier so we are looking forward to Saturday."
The Hoops will come up against an in-form Fir Park side looking for their seventh successive league win, following the a shock 1-0 Scottish Cup exit to Albion Rovers and the heavy home defeat to Celtic.
Lennon declared himself a fan of Well boss, Stuart McCall, who has guided his side up into third-place in the table.
"Stuart has done fantastically well, six wins in a row after two really disappointing defeats to ourselves and Albion Rovers," Lennon said
"He came in for what I felt was totally unjustified criticism so it shows the measure of the job he has done.
"He had a rebuilding job to do with the quality of players who went out the door, but he is still there, they are winning games and they are still right up there."