Is the baby trying to learn more about his or her environment and is fussier and sleeping lesser during the leap?

Yes, in the first phase of a leap, the fussy phase, all babies are more Clingy, Cranky and cry more. The sleeping pattern and eating pattern are disturbed. In the second and third phase of a leap, the baby is starting to explore the new perceptual world (s)he has entered and, in doing so, starting to master new skills.