Police said it appeared the boy was playing in a leaf pile in his front yard when he stepped out onto Park Avenue and was struck by a passing motorist.
"He was the love of my life. He was what I lived and breathed for everyday," said Mother Amanda Carter.
Carter said she left Kolin with his grandfather while she ran an errand. She came up on the accident scene when she returned.
"And I ran in and I screamed 'Kolin! Kolin!' and he didn't answer. I knew that was my baby down there," she said.
Carter said her son's personality likely contributed to the accident.
"The only thing wrong with my son is that he would just be over enthusiastic and too adventurist," she said.
The driver who hit Robins spoke with ABC11 Tuesday. She asked not to be identified.
"I have no clue where he came from. I don't know how it happened, how I didn't see him," she said.
The woman stayed with Robins until paramedics arrived.
"I just want them to know how sorry I am. I didn't mean for it to happen," she said. "I hope one day they can forgive me for what I did."
Kolin was a second grader at Butler Avenue Elementary in Clinton. A math whiz, his mom says made top grades and loved soccer.
"My son was so charismatic outgoing and he was just like a little angel. Everywhere he went, he touched the hearts of everybody that he ever met," said Carter. "I just want to find somebody to blame, somebody just to put the blame on, but there isn't anybody."
Carter says forgiveness will take time. For now, she has only one reminder for parents with young kids.
"I want parents to let their children know just the right way to watch the streets," she said.