At this stage of his career, Justin Bieber is only finally learning how to say no. In an interview with Billboard, the 27-year-old candidly talked about why he decided to incorporate boundaries in his life just now. He told the outlet, "I definitely learned how to have boundaries, and I just don't feel like I owe anybody anything." Bieber added, "That has helped me to be able to just say no and just be firm in it and know that my heart wants to help people, but I can't do everything." And though he's really tempted to help most of the time, Bieber confessed that "it's just not sustainable."