Jimmy Kimmel was off last week, and on Monday night's show he explained why with very personal, very heartfelt story about something his family is going through. His newborn son underwent emergency heart surgery at just three days old.

As Kimmel explained, on April 21, his wife Molly McNearney gave birth to a boy, William. Billy was born with a congenital heart condition that required surgery to fix. Fortunately, he's doing well now — Kimmel showed a photo of the adorable kid giving a little smile.

Now that Billy is doing okay, Kimmel went back to work to talk about it in a monologue that saw him fighting back tears on several occasions, including at the end when he defended universal health insurance, since no child should die because their parents can't afford medical care.

Kimmel thanked everyone who helped and everyone who sent thoughts and prayers.

"Even that son of a bitch Matt Damon sent flowers," Kimmel said.

Jimmy KimmelJimmy Kimmel