Why is Wayne Rooney not energetic or lively anymore?

When i started watching football, i saw him as very enthusiastic person who always seems to bring the crowd into the game. For e.g this goal of his against Manchester City. And the celebration afterwards was even more amazing and energetic. But this happened some 6 years ago. read more

And all the new managers started changing positions of Rooney in the team as well as on the field, as if Rooney alone could solve the problems. And because of all these changes in the clubs core formation,he was bound to get drained emotionally. read more