So, I think that I'm not alone when it comes to being confused about when は and が are supposed to be used, but here I would like to ask about a specific example
浅野君は(私に)かわいい手袋を編んでくれた
x
浅野君が(私に)かわいい手袋を編んでくれた
Is there a difference in both phrases? As far as I know (please correct me if I'm wrong), は is used to talk about already mentioned topics, while が is used to talk about new topics.