Obviously, with the release of 25, Adele's experience is bound to be obvious. Since the release of 19 in 2008 much has changed, not just for Adele but for her fans.
Adele marks her albums with the age that she was whilst they were being written, and this shows throughout most of her work. 21 was more mature than 19 and 25 will undoubtedly be the same.
Fans crave this from her; we couldn't all be sat listening to 19 again and again at the age of 25 and still relating to how she felt back then.
With age comes growth, and with growth comes experience and wisdom. This can only mean that while Adele ages so will her music, and age will hopefully have the same affect on them both as it does on a fine wine or whiskey.