Now I want to say that your ideas don't come from your brain. But of course they do, as a result of interaction with other people's ideas, some of which were written down. (Don't worry, I'm not a dualist.)

The thing is that no matter how fancy your bicycle, I can still ride my shitty bicycle to a university, and you can ride your lubricated carbon fiber bicycle into a ditch, and then you're not so smart. If what you call intelligence is how fast your bicycle typically goes into the ditch, then sure, it can be measured on a scale and you have more of it.

You, as a dualist, is the least of the fears we hold.

There are other notions about the transfer of ideas: https://www.apa.org/monitor/2010/06/memory-transfer