I have attempted, over the course of the past two years or so, to identity and eliminate any opinions I might have permitted to take hold within my brain.
Preferences? That’s different. Some people like peach cobbler and some don’t. If I don’t, that’s not an opinion, that’s a preference. An opinion says “Peach cobbler sucks,” which is not fact. A preference says “I personally dislike peach cobbler, but that doesn’t mean someone else who might love it is wrong or crazy.” My personal preferences don’t dictate whether or not something is good or bad. Nothing does.
I do like peach cobbler, though. That is a fact. If I said “Peach cobbler is delicious,” that would be an opinion. I don’t like opinions. That is a preference. Are opinions entirely useless? Ah, see, that’s the tricky part. That’s an opinion, and I reject it as such.
Patrick Walts 
I went through a similar process a few years ago. Well, I say that like it’s over, but of course it’s not. It’s an ongoing thing.
Anyway, it’s good to reexamine your opinions and beliefs on an ongoing basis. It’s hard work, though, which is why so many people are so unwilling to do it.
It’s taken many cycles of me looking back on myself in years prior and going “Ugh… WHAT?” to arrive at a place where I recognize that just because I don’t like or understand something, that doesn’t mean it’s invalid
Or, people will give advice like “Ya gotta do THIS.” You don’t, though, in most cases. I prefer “Well, what worked for me is as follows.” What works for one person might not for another. There are a number of ways to accomplish most goals. Many roads lead to the same destination. People think their road is the best and every other road is stupid. I used to be like that. I think it’s human nature. I’ll speculate all day and operate on what I decide the best course of action in any given situation, but I try to keep myself open to alternatives.