matchmaking seems off

Heyo everyone,

I've played league for a while now, and my new account (old one got banned, not the point here), was level 25 when i was getting consistently ranked with people of gold and up.

this has bothered me, because most games I get absolutely stomped in lane, leaving me useless and even more trampled upon in the teamfight stage.

I was wondering if anyone can explain why the matchmaking system sees fit to rank me with such high level opponents, since I myself am pretty sure i shouldn't be. my old account was silver 5, and since I lost it I haven't played much at all, in fact, in the last month i've not played for 3-ish weeks straight!

my mechanics are rusty, my game knowledge is out of date, and my opponents get stronger.... I understand skill-based matchmaking is a thing, but i don't really think it's applicable here, since i've never played on that level before. does this mean that for some reason i'm just extremely good all the sudden, or could there be something going on with matchmaking.

PS: The one time i got ranked into a game of all my level accounts i got vs a riven main smurf, which actually got me to ragequit for the first time in like, forever so that was fun.