Robins admits he should not have asked to leave United before heading to Norwich City.
He told Inside United: "I'd asked to move on because I wanted to play.
"It's one of my regrets. Sometimes you make a decision when you're headstrong and young and make decisions for yourself that you think are right when you really haven't got a clue.
"That was the category it fell into. I should have stayed and waited as the season I left, they won the league. Being young, you don't know how it's going to pan out and, in hindsight, and hindsight is brilliant, I would have stayed a little bit longer.
"The gaffer did offer me a three-year contract which, looking back, was absolutely generous but, me being me, I decided it wasn't for me and I needed to go and play. Yet I was at, for me, the best club in the country by a million miles and I should have scrapped to stay and hang on in there.
"After you've made decisions, you can't afford to have regrets and I had good times at every club I went to and played for but nothing replaces the feeling of playing for a club like United, without a shadow of a doubt."