The Scottish champions host the Italian side at Celtic Park on Tuesday and after their morale-boosting victory over Barcelona in the group stages, Lennon is confident his side have nothing to fear in the last-16 encounter.
"When I took on the job I didn't imagine a game like this, when you consider where we were and the progress that we have made," Lennon told The Guardian.
"What I did think at the start of the season was that if we could get through the qualifiers we could make inroads in the Champions League with the players that we had.
"We don't want to stop now at the last 16. We've got two titanic games against Juventus to look forward to and anything can happen over a two-game tie."
Juventus could hand a start to new signing Nicolas Anelka, although Lennon says he is not concentrating on the Frenchman.
"I think they're pretty top-heavy at centre-forward," he added. "I don't know how much football Anelka has played in the last few months, so whether he's been brought in for domestic football or this game, I don't know.
"We had them watched against Fiorentina on Saturday but we know that whatever two strikers they use will be quality. They are pretty clinical in the final third so we'll have to be at our best."
Celtic approach the game on Tuesday on the back of a 3-1 victory over Inverness and winger Kris Commons, who scored during Saturday's win, is hoping for a massive occasion.
"It feels like it's been a long time coming, probably about two and a half months, so I just hope it doesn't pass us by," he said.
"We have to take the opportunity by putting in the kind of performance that we know we are capable of at Celtic Park.
"I don't think this is a tougher proposition than Barcelona. We fancy ourselves over the two legs. We're quietly confident."