Now during that time I thought pantheism was normal Yiddishkeit. I had no reason to think otherwise.
Now most of that time I knew that pantheism was at least defensible because of Spinoza. But some questions started popping up about Spinoza. I read a book about Aristotle at Hebrew University and the author made a point to mention that Spinoza puts more constraints on substance than does Aristotle. I realized just take away those constraints and the whole edifice falls. Later in Netivot I saw the critique of Leibniz. Now all this time I knew that pantheism is not mentioned in any traditional authentic book. But the way Rav Shick was presenting it was that it was some deep secret that they were hiding.
The thing that convinced me that Spinoza was not correct was that I discovered the website of Kelly Ross. I discovered that website when doing some research on Spinoza. It was not any particular question Kelly Ross asked, but the problems between the empiricists and the rationalists and the approach of Kant that convinced me that Spinoza was just one step towards some proper approach.
Now we know the approach of the Rambam and Saadia Gaon is Monotheism but without the Kant school it is very hard to brings Maimonides down to earth in a concrete easy way to understand.
The Guide of the Rambam is known to be dense and difficult.
Another thing which woke me up was an essay by a person that had been in some Hindu cult in Southern California. The author had some critique along the lines that thinking everything is God doesn't make people better. (The same author also wrote a book Saved from the Darkness. His name is Brad Scott, I think)