The Hulk star's son, Kai, enrolled at Yale University and she drove him to the prestigious school at the start of term.

Connelly admits she was able to keep her emotions in check while she was in Kai's presence, but totally lost it on her way home.

"It really took me by surprise... when he left," she told U.S. breakfast show Live! with Kelly and Michael on Tuesday (10Nov15). "I tried to play it really cool, dropping him of at school, I kept it together, tried to be dignified about the whole thing, left him, closed the car door, drove away, sobbed.

"Not like little tears that you could clean up with a little tissue... I sobbed. Full on, snotty, awful, the whole drive home, three hours, and then the whole night. The (next) morning, I had a mascara massacre on the pillow and the next day if anyone touched me, I burst out crying. So awful, but it gets better."

"The happy ending was I couldn't wait for parents weekend, the very next weekend," she continued. "I drove down to see him and he was so happy and he had made friends and he was taking initiative and was so settled and so clearly ready to be there and it all kind of went away. I mean, yes, I miss him, but it completely overrides my (other) feelings."

Connelly's boy is studying physics and calculus, and his proud mum reveals he's interested in engineering as a career.

"I was interested in physics and I started out thinking that maybe (I would major in something pertaining to it)," she gushed.