How does Dua really work?

For example, if i am lazy and i make dua to Allah to not make me lazy, will i suddendly become energetic and active? Or if i am a dumb person and i make dua to Allah to make me smart and give me knowledge do i suddendly become smart? If to become smart i have to read and learn, then what is the point of making dua anyway? All i can think of where dua is helpfull is for the hereafter, for Allah's forgiveness, to go to Jannah etc. What if you make dua and pray salah for weeks and months and nothing has changed in your life? Is it because i am not making dua like i am supposed to or the dua has not been accepted?