Like every child he doesn't face happiness in his childhood. Story start from scene where he ( Dr. Depressed) is enjoying his school life & getting price for having 🥈 number in exam.
He's personality is out of imagination, he's charming and all students, teachers & principal loves him. That day he went home and saw his parents fighting. His joy go away. There's something wrong with his father and he gets frustrated at everyone and slap her mom. He's father do this every month like it's his daily routine. These types of nonstop events took Dr. depressed's childhood happiness. Now Dr. Is being sad all Time enjoying nothin at all.