"That was a big part of our marriage that I had to check myself because she was like 'I have goals and dreams too'."
Brady stated he wasn't aware the successful supermodel and businesswoman had aspirations outside of the home, and he realised he needed to "make a change".
The quarterback made some changes to projects in order to be home more, but then became "resentful" towards Bundchen, causing the supermodel to write a letter to him that changed everything.
"She actually wrote me a letter, and it was a very thought out letter that she wrote to me and I still have it and I keep it in a drawer and I read it," he said.
"It's a very heartfelt letter for her to say this is where I'm at in our marriage, and it's a good reminder for me that things are going to change and evolve over time.
"What happened and what worked for us 10 years ago won't work for us forever because we are growing in different ways."
The couple decided to attend counselling and managed to find a way forward to ensure both of their happiness.
"The point of a relationship is that it has to work for both [partners]," he said.
"You better work on both because if you don't then it's not sustainable."
