The Paisley battlers came from behind to clinch their first major silverware since 1987 with a 3-2 victory over Hearts at Hampden.
St Mirren struggled early on and trailed to Ryan Stevenson's early strike, but an Esmael Goncalves goal took the teams into the break on level terms.
And after Lennon delivered his half-time euology, Steven Thompson netted a minute into the second period and Conor Newton added a third before Stevenson pulled one back five minutes from time.
"Yes. I got into the players at half-time and reminded them that if they wanted to become legends there was a game of football to be played," said Lennon.
"Our problem in the first-half was that we didn't pass the ball. Hearts came out the traps well, they were one-up, they had the better opportunities and probably the only opportunity we had, we took it.
"That would have deflated them a little bit and gave us a lift but it was not the lift that got us started, that came when we got them in at the break.
"There was a little bit of emotion, there were raised voices, some comforting words but more importantly, I reminded them that these opportunities don't come very often.
"Some players will play their full career and never get the opportunity to play in a national final in the national stadium, so my message to them was make sure that it was a day that they could remember for the rest of their lives.
"I hope it is the first of many, but I may not get to another cup final. I always said I would enjoy every goal if I got to a final and I wanted to enjoy it with the fans.
"I am very proud, very emotional and absolutely thrilled that we are bringing the trophy back to Paisley for the first time in this club's wonderful 135-year history."