Think of each of these systems as a language that you could speak. If you know English, you could probably learn Spanish easier than Russian or Thai. The alphabet is the same, the verbs have similar kinds of conjugations, etc. But it is still a different language and you’d need time to learn it. Also, to be conversational is necessary to have a conversation, but if you want to write a book in it, you’ll need to be fluent. The same is basically true for computer languages.