Jamaican Gayle scored 317 out of the West Indies' total of 565 for five, which they made in reply to South Africa's first innings of 588 for six declared.
Lara made the world record score of 400 not out against England at the same ground in 2003-04.
"I was trying to get as close as possible to 400, but it didn't happen and I'm satisfied with my performance," Gayle told a news conference.
"It would be a long way to come back if I had to start all over again. When will I reach this stage again?"
Gayle's innings was the highest by any batsman against South Africa and the 14th highest in Test history.
But he had been focused on Lara's milestone only.
"The only record I was thinking about was the 400," Gayle said.
Gayle batted for 10 and a half hours, faced 483 balls and hit 37 fours and three sixes.
He said he felt the strain of his long innings as it dragged on.
"I take it session by session and build from there, but just after lunch I found myself lapsing and I called for some water," Gayle said.
On Sunday, when he reached 184 not out, Gayle dedicated his innings to his mother, Hazelyn Gilroy.
He said he had telephoned her after Sunday's play.
"She was very happy, she said, 'Go get the next one'," Gayle said.
Gayle hoped his innings would prompt the Jamaican government to allocate more resources to cricket.
"They're focused on football, which has become the number one sport in Jamaica, but they could take a lot more interest in cricket," he said.
