For some parents, their children grow up so fast that it’s easy to forget just how hard it was taking care of them as newborns.

That was the explanation Jessica Alba gave to Jimmy Fallon Friday on “The Tonight Show” when she and husband Cash Warren decided to go for baby No. 3.

“I have amnesia about having a baby which is why I allowed this to happen,” Alba, 36, joked as Fallon reminded her of the sleepless nights.

The actress’s guest spot on “The Tonight Show” was her first public appearance since announcing her pregnancy on Instagram in July, with an adorable photo of her daughters holding up balloons shaped like a “1” and “2,” while Alba held up “3” and placed her hand on her belly.

Finding an unusual baby name is also now on the agenda.

Alba wants to stick with a single or double-syllable “H” name that is also a word on its own.

TODAY. Jessica Alba discusses baby name options on the “Tonight Show.”.

Fallon didn’t take the hint and suggested names like “Herman” and “Hail,” and “Hale”.

It’s safe to say Alba will need to keep looking for baby-name inspiration.