He would have verbal fights with his school teachers, and often get into trouble over his hair or attire.
Mr Asher Chua would also play truant a lot till his parents had to be called.
Sometimes, he would even catch a nap in an HDB block nearby till school was over.
But the person who once did all those things has since changed his attitude so much that come tomorrow, he will be graduating as the second top student of Republic Polytechnic's Diploma in Mobile Software Development (School of Information).
He got mostly As and his grade point average is 3.81.
Mr Chua, 20, has also been inducted into the Director's Roll of Honour for four semesters.
Looking back at his past, he said: "It was an experience. Without it, I wouldn't be what I am today. It was a bit rocky but it was probably necessary for it to happen."
Still, it wasn't easy to get to where he is today.
Mr Chua recalled how he used to try to avoid school when he was studying at Yuhua Secondary School.
"My parents would say they were okay with (me not going to school), but I noticed them getting more and more disappointed in me. I saw it in their eyes," he said.
In Secondary Three, the Express stream student finished last among his cohort and was told he would either drop to the Normal Academic stream or be retained a year.
Mr Chua chose to drop out. He was 15.
He worked at part-time jobs for three to four months - serving at a fast-food restaurant, distributing fliers and even selling ice cream.
He also helped his father, a cleaner at a Kopitiam outlet, to collect trays.
He recalled how his dad would leave home early in the morning and get home late at night.