Fatt's schtick was sleeping at odd times, which led to a Wiggles catchphrase and the title of one of their songs, "Wake Up, Jeff!" Fatt was the oldest Wiggle and was well known for his "laid-back personality", which according to Field, made him "invaluable company on the road". As Sam Moran has said, when referring to the development of the Wiggles' shticks, "Jeff really does fall asleep", and Fatt reported, "The irony is I'm a very light sleeper in the nighttime. I will invariably have a snooze before the show". Fatt was the only member of the Wiggles without a background in early childhood education; he stated that was the reason falling asleep was chosen as his shtick, "because it was a way of getting me involved in the shows without actually having to do anything". Field claimed Fatt's shtick endeared Fatt to their audiences and called it "a simple audience participation and interaction gag we've done since the start of the group". Kathleen Warren, the group's former professor at Macquarie University and their consultant for their shows and DVDs, believed that the shtick empowered children, and Paul Field reported that children in the Wiggles' audience felt "great excitement" and were disappointed if not given the opportunity to help Jeff in this way. Anthony Field reported that although in the early days of the group, they took turns falling asleep, it became Fatt's shtick because "it was a perfect fit".