Ashlee Simpson learned to say “no” because of her ‘Saturday Night Live’ lip-syncing fiasco.

The 39-year-old star appeared as a musical guest on the long-running TV comedy show back in 2004 – but after losing her voice on the day of her performance, Ashlee suffered a series of technical issues that led to a disastrous performance and widespread criticism.

During an appearance on the ‘Broad Ideas With Rachel Bilson and Olivia Allen’ podcast, Ashlee said: “I’ve never talked about or said, but it’s like the other thing is, learning as a woman, when you say no or as an artist or a human or whatever, that day I said ‘I will not go on, I don’t care. I can’t speak.’”

Ashlee appeared lost and embarrassed amid the lip-syncing fiasco, and the singer actually feared that something would go terribly wrong before she even took to the stage.

She recalled thinking: “My band has never practised this, this is not going to go well. I can’t do this.”

Ashlee was slammed for lip-syncing on the TV show – but the embarrassing incident has taught her an important life lesson.

The pop star said: “I feel like it was a humbling moment for me.

“I had the number one song, it was, like, everything was about go, like, somewhere and then it was just, like, woah. The humility of not even understanding what grown people would say about you, awful, awful things.”

Ashlee actually returned to ‘Saturday Night Live’ in 2005. However, she hasn’t been able to find any evidence of her performance online.

She said: “I went back to ‘SNL’ with my second album and I can’t find it anywhere. I’ve searched and searched for that performance. I was really nervous when I was on there and I can’t find it anywhere.”