If you’ve never been in a relationship, then you should not give relationship advice or discuss relationships. If you don’t know anything about film, film history, storytelling, editing, etc., then you should not discuss the Oscars or Oscar-nominated films. If you’re only into MCU movies, then no—you aren’t a real Marvel fan and should not discuss Marvel. If you don’t have experience in a subject, then you shouldn’t discuss it.
There’s a difference between discussing something and speaking as an authority on a topic. I have a coworker who parrots the saying, “seek to understand before seeking to be understood”. Nobody understands everything about anything. Having conversations and learning from them are part of gaining knowledge.