New Kids On The Block star Joey McIntyre has warned Justin Bieber about the pitfalls of finding fame at a young age, insisting he endured plenty of "dark days" after his boy-band heyday.

The singer shot to fame when he was a teenager as the youngest member of the pop group, and admits he was in for a shock when their popularity waned.  Now, he's urging 16-year-old Bieber to surround himself with loved ones to support him through his "ups and downs."

McIntyre tells Entertainment Tonight, "I wasn't perfect. We weren't perfect. We certainly made mistakes and there were dark days. You're the biggest thing in the world (but) you gotta come down. What goes up comes down, for whatever reason. "

"You gotta learn how to hang in there and know that there's so much more to life than just singing pop tunes and dancing around on stage. And that takes a while - everybody's got their own path and their own time."

"You have to go with the flow and learn some things the hard way. Hopefully kids like Justin - there's a lot of young artists out there - hopefully they've got good family around them and they're able to take the ups and downs."

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