OP.GG Confuses me

So, going on OP.GG, I check my stats out. Pretty average stuff, but then the site tells me I was Gold 1 with 17 LP during season 5. I wasn't even level 30 back then, but people find me and call me a boosted animal ( They aren't wrong about the animal part) and this really confuses me, so somebody tell me what's going on :L