Why would you even talk about it if you know nothing about it? I believe that's a problem for people who don't know what they are discussing. They push themselves to let others see that they are knowledgeable about something, but when it comes to application, they don't know what they are doing.
It's like researching and not knowing what to do with the knowledge. I think it's important to have that firsthand experience if you advise someone, but if you are just going to talk about it, I think it's okay. It would depend on how the conversation goes, like if they are going to be talking because that person is interested in learning.
The important thing at the end of the day is that people understand the positioning that they have, whether it's about experience or not, that gambling can be addicting and it needs to be controlled.
Most of the time, we can observe that experienced gamblers think that they are better and more knowledgeable. Of course, we can't deny that they already gain more knowledge, but having an opinion from beginners could also help, not in a way they could teach us but for us to know their sentiment and level of understanding. Maybe in return, we could help them improve and correct their mistakes.
The discussion is not about who is good at gambling but rather an exchange of ideas and opinions. If we think he/she is right, then we also acknowledge it rather than pushing ourselves that we know everything.