'Be a man': Donald Trump attacks Jimmy Fallon after finally learning the host regrets his puffy interview in 2016
'Tonight Show' host Jimmy Fallon plays with Donald Trump's hair on Sept. 15, 2016.

During his Sunday Twitter storm, President Donald Trump evidently learned that Jimmy Fallon regretted his fluffy and meaningless interview with the then-candidate in 2016.

".@jimmyfallon is now whimpering to all that he did the famous “hair show” with me (where he seriously messed up my hair), & that he would have now done it differently because it is said to have “humanized” me-he is taking heat. He called & said “monster ratings.” Be a man Jimmy!" Trump tweeted.

Stories about Fallon surfaced in 2017 when his ratings began to sink.

“They have a right to be mad,” Fallon said in a New York Times interview in March 2017. “If I let anyone down, it hurt my feelings that they didn’t like it. I got it.”

"I didn’t do it to humanize him. I almost did it to minimize him. I didn’t think that would be a compliment,” he later said.

The mea culpa then hasn't helped, however. He went further this week with his apology in an interview with the Hollywood Reporter.

“It was definitely a down time,” Fallon said of life after Trump's appearance. “And it’s tough for morale. There’s 300 people that work here, and so when people are talking that bad about you and ganging up on you, in a really gang-mentality…”

Fallon even got a little choked up, continuing, “You go, ‘Alright, we get it. I heard you. You made me feel bad. So now what? Are you happy? I’m depressed. Do you want to push me more? What do you want me to do? You want me to kill myself? What would make you happy? Get over it.'” Fallon adds, “I’m sorry. I don’t want to make anyone angry — I never do and I never will. It’s all in the fun of the show. I made a mistake. I’m sorry if I made anyone mad. And, looking back, I would do it differently.”