Confused about this phrase from a podcast

Hello! I've been trying to work on my listening comprehension and I came across this phrase in a podcast that I can't quite grasp. For context, the speaker is talking about new exchange students he has made friends with at college:

私の持っていなかったイデアがあったり、英語で毎日話しをしたりして、とても面白かったです。

I'm struggling to understand what the first phrase is saying, it seems like "私の" and "持っていなかった" are conflicting in my head.

by guywithhelmet