Riddle: Who Am I?

I was your leader, I held the country, but most of you went on to call me dumb. All sorts of names. You unseated me while I was ruling, now most of you wish I was still in office. To you lots, life has become unbearable, everyday you cry on twitter, you buy fuel for N145 now. A bag of rice is almost N20,000, beans you cant even tell. But during my time, there was food in abundance, you had money in your pockets.

Now most of you want me back, I am not coming back. I am fine going around the world and speaking about good governance. Duh! So do you know who I am?