Maria Bartiromo: The lessons I've learned from Jack Welch

I've known Jack Welch for more than 25 years. He was my big boss at CNBC when it was owned by GE and he was chairman and CEO.

He was a very hands-on manager so I got to talk with him a lot while there. Later, he became a regular guest on my show while at CNBC and throughout my years in business and especially after I left, he and his wife Suzy became good friends. We would have dinner together.

FORMER GE CEO JACK WELCH DEAD AT 84

He was an incredible leader. He was among the people who supported my going on the floor of the NYSE and becoming the first person to broadcast from there. He loved CNBC and was proud of it. He was always giving us ideas about how to program it. Later, he started the Jack Welch Management Institute after he stepped down from GE, so emerging professionals could better understand his business principles.

He taught me a lot. His legacy will be all about leadership and accountability. He held you accountable for your commitments. But he also celebrated and took note of your wins. One of his regular moves was to send handwritten notes to people. I received several notes from him telling me how great I was doing or thanking me for a job well done. It made me feel like a million dollars to receive a note from Jack. And it was so smart of him because all it did was make me want to work harder for him and for the company so I could receive another note!

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He was such a smart manager. He pitted people against each other in some ways, which made them compete and work hard to win, but it also stoked jealousy and competition, which was criticized later. It's hard to argue though that he was not an incredible manager. His own transition, however, did not go as well. He regretted putting Jeff Immelt in as his successor in running GE, and in retrospect he was right. The company faltered hugely under Immelt, and Jack's stock along with every other shareholder, myself included, plummeted. Jeff tried to un-Jack GE, changing many of Jack's policies and culture.

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This was his biggest regret in life. He was also loathed by some for certain management decisions he made. He made it a point to fire the bottom performers regularly. He was a tough boss. But he respected hard work. He once told me "control your own fate, or someone else will." This stuck with me for my entire career. It was so educational for me because it said to me "you are accountable for your actions and they will have an impact." It was one of the most important lessons I learned from Jack. I am grateful for him.

One of his biggest joys in life was his third wife, Suzy. She rekindled love in his life and was on the same wavelength of his in terms of loving business and wanting to write about it and sing it from the rooftops. She was the editor of the Harvard Review and they met after she did a cover story about him. It turned into a big scandal at the time. But eventually, they married and she helped him write books and became his speaking partner at conferences.

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The decision to get together was tough because it was a public affair written about in The Wall Street Journal and it kicked off a nasty divorce battle, which opened up a Pandora's box of dirty laundry about his salary and benefits -- the package he received after departing GE, including private jet use and the value of his stock. But they got through it and stayed together and blossomed as a couple. She took care of him.

I have a ton of stories about Jack and I'll share more tomorrow on "Mornings with Maria" on FOX Business starting at 6 a.m. ET.  I'll show some pictures too.

I send my love and condolences to Suzy, and Jack's family and friends.