I feel like it is exactly similar to learning anything else. You learn the cards, you learn what is better than the other thing, you learn the odds, you learn basically whatever people teach you, like for poker, there are poker courses and it teaches all you need to know, there are beginner level classes at first, but then you can do advance as well if you want to.
There is nothing humans cannot learn which was invented by another human. It's all about the seriousness and interest. I did not bother to learn card games or take them too seriously because I don't live with friends. I meet them once in a while. My family members don't like card games because they believe I can start gambling. Well, They don't know I can gamble on the Internet. This is not the main reason. I didn't take it that seriously because all my friends lived in different cities because of their Jobs. So, I didn't find enough time to spend with them so I could enjoy and learn.
For Gambling, I can choose other games as well. There are a bunch of popular games that I can try without actually knowing how it works. I remember I started playing slots without knowing how it pays.