Robbie Williams listed off some of his regrets during last Friday night's filmed-for-TV gig at The London Palladium.
He said: "For a long time, as long as I can remember, I've felt a little bit stupid. I left school without any GCSEs, nothing higher than a D.
"I'm the first to admit I've made a couple of mistakes."
Listing some of his regrets, he said: "Two trips to rehab. Rudebox the album. Geri Halliwell - I should have gone for Victoria really, shouldn't I? I'd have been really famous."
He then apologised for his remark to the former Spice Girl saying: "Sorry Geri Halliwell". The pair dated for a few months in 2000.
Williams also spoke about his daughter Theodora Rose, describing her as the best thing that had ever happened to him.
He said: "I took her to nursery for the first time two days ago. She learned to walk ten days ago. She's the love of my life."
His new single, Go Gentle, was written for his daughter.
Here's the video for Go Gentle: