It's a big day for Justin Bieber and his fans — five years ago today the pop star released his very first single " One Time"! (Can you believe it's been that long?!)
All day Beliebers have been tweeting about how proud they are of Justin, even trending the hashtag "#5YearsOfOneTime."
This Vine pretty much sums it all up:
To celebrate, we rounded up 10 photos of baby Justin that will give you serious nostalgia. Click through, then let us know which pics you love the most in the comments below. Can you believe it's been five years since "One Time" became available on iTunes?