Right at the height of Efron's teen-king fame in 2009, he starred in 17 Again as Mike, a 37-year-old (played by Matthew Perry) who becomes his 17-year-old self again through a magical accident. Suddenly turned into his teenage self but stuck in his current era, Mike poses as his adult best friend's son to enroll in high school and try to figure out how he got turned into a teenager and, more importantly, how to undo it. During his time as a teenager, though, he starts to learn more about his estranged wife and their teenage children, leading him to figure out the problems in their life that he hadn't been able to see before.
Watch 17 Again on Netflix.