Adele was "more aware of her own flaws" when making her second album.
The 'Cold Shoulder' singer worked with super producers Rick Rubin and Paul Epworth on the follow up to her debut, '19', and said her new, more mature, approach is reflected with the title of its follow up, '21'.
She said: "It's taken a while and it knocked me for six when writing it. It's different from '19', it's about the same things but in a different light.'
''I'm more patient, more honest, more forgiving and more aware of my own flaws, habits and principles. Something that comes with age I think. So fittingly this record is called '21'."
Adele, who is now 22, has previously told how she took her time with her album because she wanted her sound to progress, but was careful not to alienate the fans she won with her first album.
She said: "I'm a bit scared. Obviously there are new avenues that I want to go down with the sound and I don't want to leave behind the fans who might not like the new sound I am going for, so I'm a bit wary of that.
"I'm writing it slowly but surely. I didn't want to tell anyone who the producer was until the record was done, in case it flops."
'21' will be released in January, with a single 'Rolling In The Deep' scheduled to precede it.