But it was a different ball game once the cameras were rolling, Mr Lee revealed on Thursday (Aug 24), as he shared a video of his bloopers while filming.
"Last week, I tried something new," Mr Lee wrote on his Facebook page. "For my trailer for the National Day Rally, I had to walk and talk at the same time. TV personalities (especially David Attenborough!) make it look easy, but it is harder than you think."
In one of the takes, Mr Lee began with "Hello! This year, I am talking about upgrading our pre-schools ..." but cut himself off as he took a few steps towards the camera and promptly lost his train of thought.
"Once you walk, it's all ..." Mr Lee said in the video, laughing as he threw his hands in the air.
"I am not quite Wonder Woman," quipped Mr Lee, referring to Mdm Teo Yoke Lan, the 70-year-old tech-savvy UberEATS courier he cited in his Rally speech.
"But after a few tries, I finally got a 'clean take'," Mr Lee added.
Netizens had praise for Mr Lee's decision to put up the blooper reel.
In his Rally speech, Mr Lee highlighted three longer-term issues that he said are important to Singapore's success and well-being: Improving pre-school education, fighting diabetes and making Singapore a Smart Nation.