Milo Ventimiglia would "never" date Hayden Panettiere again.
The 40-year-old actor romanced his 'Heroes' co-star for two years until 2009 and though he "wouldn't change a thing" about his life, their relationship - which began when he was 29 and she was 18 - isn't something he'd want to repeat.
Asked what he learned from their relationship, he said: "Never do it again.There are things that happen to you in your life that shape who you are. Everything I've been through from jobs to friendships to partnerships, everything has built me to who I am. You learn from it. You learn a better way of doing things.
"It wasn't until my mid to late '20s that the job wears on you, relationships wear on you. But I wouldn't change a thing. When you get knocked over the head in life, it builds your perspective."
The 'This Is Us' actor - who shot to fame in 'Gilmore Girls' at the age of 24 - also revealed another of his big regrets, dropping out of college.
He told Mr. Porter's The Journal: "I realised I had to let school go. There's always one thing I wish I could have done - finish."
When it comes to starting a family, Milo is leaving things up to fate and wouldn't be too upset if he doesn't have any children because his legacy will live on through his work.
He said: "At some point. I'm sure I'll be a father when I'm meant to be a father. If I never have kids, then I was never meant to have kids as well.
"In entertainment, sometimes being a known person, you get to pass that on to a larger group of people than just your kin, than just your immediate family. You're able to, hopefully, give something good out to a larger group of people."