Memorising mindmaps

Hello guys! This is my first post so I am glad to have found this community, I think that it is great!

So my first post then will be about memorising mind maps.

I have been using a study system from the spanish memory champion Ramon Campayo. He says that should be pretty straightforward to memorise a small mindmap, however, I have been doing maps for around 1 year and a half of every single chapter of every subject, and I am still not able to memorise them. Yes, I can but I have to invest more effort for that than for the whole rest of the subject, which is pointless. So it makes me think that I am doing something wrong? Maybe I should look for some kind of training before going to such complicated task.

What do you think?
Thank you very much!

I recommend checking this topic: https://artofmemory.com/forums/help-memorizing-mindmaps-5821.html