Christian monks shaved the center of their heads, while Jewish people wore a patch over that center instead..why is that? I've always wondered.

I did not know the answer to this until I started healing internally. Once I connected through my own spirit to higher dimensional self (light) through my open crown chakra, many truths became self evident. Later, I learned the answers to your question - however, I do not think that many people on Earth understand the answer, despite their own adherence to the respective religious doctrines.

Light enters from spirit through the crown chakra in the non physical energy body of humans. This is the origin of drawings of Jesus and others with rings of light around their heads. I am not 100% sure about the monks in Christianity but I imagine their head shaving relates to that. I do know that the Jewish headgear is meant to symbolically block out God's light from them as they are 'in exile'.