"I still feel her looming presence behind me, saying 'You said you were only going to speak 30 minutes so make sure you don't go beyond that," Bush told a crowd at the 11th Annual Elmhurst College Governmental Forum.
Barbara Bush died Tuesday at the age of 92.
He told the crowd that his mother would have wanted him to attend the forum because he had committed to do so.
"If she was here, she'd say, 'Thank God you made it,' because she would have been very upset if I stayed home," he said.
He said his mother was his first teacher.
"I'm so blessed to be her son. She taught us to be civil, she taught us to love your family with your heart and soul," Jeb Bush said of his mother.
WATCH: JEB BUSH TALKS ABOUT MOM DAY AFTER HER DEATH
He ended his comments about his mother with, "I love her dearly."
Jeb Bush talked about leadership in a changing world at the event, which was being held at the Hilton Chicago/Oak Brook Hills Resort in Oak Brook. He participated in a Q&A with Chicago Tribune Publisher and Editor-in-Chief R. Bruce Dold.
During the discussion, Jeb Bush also talked about his dad, former President George H.W. Bush. The couple were married for 73 years.
"He held my mom's hand all day long yesterday. She passed in the early evening and I called him and he said, 'I am kind of a crybaby right now. I am not feeling very good,'" he said.
Elmhurst College officials reached out to Jeb Bush Tuesday night to see if he would still be able to serve as the keynote speaker.
"We scheduled for him to come months ago and only recently learned that his mother was so ill and we were wondering," said Desiree Chen, of Elmhurst College.
FAMILY FRIEND REMEMBERS BARBARA BUSH
Jennifer Dolan was a student at the University of Illinois when George and Barbara Bush were in the White House but her father was the commander at Andrews Air Force Base. The families spent a lot of time together and Jennifer remembered the kindness she always received from Mrs. Bush.
"Every time I'd see her she just had this smile on her face," Dolan recalled.
Dolan remembered Bush as much more than a family friend. When her parents golfed with the then-president and first lady, she got to babysit their dog Millie.
"My mom didn't know how to drive a golf cart. Barbara said, 'Have you ever driven one of these?' She said, 'I'll drive.' She was so down to earth," she said.