Most Catholics I have met outside of the TLM communities have actually been heretical in some way.
Now, when I have been able to do so, I have corrected the errors of faulty thinking, realizing that most Catholics have not had good catechesis. Whether the beginnings of their teaching was false or not, by the time one is an adult, one must learn to true faith.
Reason is part of who we are. Therefore, to ignore the rational part of us is to ignore a key gift of God to us as humans-our rational nature.
If one is a heretic at the age of fifty, it is one's own fault. There are so many places to find out the faith, that there is no longer, in the Western World, an excuse for invincible ignorance.
If one desires to find out something, one looks until one finds that knowledge. There are some things which are self-evident, but missed because people are simply not paying attention for a variety of reasons.
We have sufficient reason to be rational Catholics.
We have faith which informs reason.
We have speculative and practical reason. Speculative reason examines the nature of things, asking the questions Who is God; Is there a God; Why are we here?
Practical reason asks questions such as Why is this good and this evil? Is this action good?
If we are not asking questions,we are not using the gifts which God gave us as humans.
We are responsible for what "goes into our brains."
What are you putting in your brain? What are you reading, listening to, watching?
On these things, we shall be judged.