Yep.
If you owe the debt and he legally purchased the debt, then he can collect on it.
He can't garnish your wages without a judges order... sounds like you missed a court date. Had you shown up to court you could have argued the statute of limitations and avoided this mess.
Contact the court and get a copy of the judgment filed against you. You should be able to obtain documents that show how you were legally served notice of a hearing. If you were never served or not properly served then you may be able to do something.... maybe.