About irony. I've come to the opinion that it doesn't exist as a rule. That is to say, if it happens as an exception it can be ironic, but there is no such thing as consistent irony.
I've moved towards this point of view after realizing two things: 1) If something is repeated it becomes "true". True defined as the correct response to a situation. 2) If something is repeated it becomes meaningless. This happens when "truth" is so pervasive that it no longer depends on context. When the meaning of a word or phrase comes from how it is used, being universally true is the same as not having a rule for how to use it. It has 0 symbolic meaning left.
Notably, these don't happen at the same rate, and your brain tries not to let the second happen if it can help it. Boredom usually works well enough. The tricky thing is when they operate at different levels. If all the humor you are exposed to is racist, but you "aren't racist", you can try to avoid letting racism become true to you but still have it be so ubiquitous that it becomes meaningless. And a person who sees racism as meaningless will perpetuate racist social structures with nary a conscious action taken. Be careful what you say more than once, and how you'd change if the person saying the same things as you meant them.
This isn't to say humor or fiction don't exist, just the opposite. Humor is never "just a joke", it exists. Outright lies exist. And everything that exists can be learned from. I might just be advocating for more critical thinking, but I think its a bit more complicated than that. The ability to deradicalize ideas you say you don't believe in your heart out of yourself is not one I've seen taught anywhere.
tl;dr Make sure you become the person you claim you are or you'll become the person you imply you are.