Zac Efron [1] has a lot of respect for his fellow Hollywood star Leonardo DiCaprio [2]. On Thursday, the Baywatch [3] actor gave a sweet shout-out [4] to the Oscar winner [5] and self-proclaimed environmental activist [6] on Instagram. "RESPECT to @leonardodicaprio for his tireless work fighting for our environment #🙌🏼🙌🏼🙌🏼 #LDF #InstagramKindnessDay #TBT," he captioned a throwback photo of the two at an LA Lakers game in November 2008. In the snap, Zac is sporting his old shaggy haircut from his High School Musical days [7]. Oh my, how things have changed. We certainly wouldn't mind seeing this friendship strike up again.