The singer's latest single 'Candy' is on course to become his first UK number one single since 2004.
Williams explained that he has realised that his career is about making successful pop hits, following a lack of number ones from his previous three solo albums.
"After the first four or five albums, when you are at the top of the pile, suddenly you start to hear, 'This is s**t, Robbie is s**t'," he told The Sun.
"And then you start to think, 'Oh God, maybe I am s**t and I should try something else and be interesting'.
"So I went off to try to be interesting and I didn't write a hit."
He continued: "When you have everyone telling you your album doesn't have a first single, it shoots at your confidence.
"So I thought, 'F**k you - if you don't think I can write a single then I'm going to rejoin Take That'. And I did."
Speaking of his current hopes, he said: "I get what my purpose is and what I want to do. I want to write big pop hits, sing in stadiums and have people smile and rejoice again.
"I'm still young enough to have the backing of people like you to find time to come to interview me and for radio stations to play my songs. I'm still young enough to conquer the world - and I'm going to try."
Williams also spoke about his future with Take That, and stated that he would definitely return to the group if they ask him.
He said: "I really don't know. It's up to them, really. I am ready, willing and able, whenever they want me to do anything with them.
"But I hope that happens sooner rather than later."
Looking ahead to his career in 2013, he added: "All I know is that now I've got a really big, gleaming pop album that can spearhead the next 18 months for me in a really good way.
"Success is addictive and I believe that I've got the album to feed my addiction for 18 months. And I am very excited about that."
Robbie Williams will release new album Take The Crown on November 5, while its second single 'Different' will follow on December 17.
Watch the video for 'Candy' below: