A good thing of studying at the university is that you enter into a universe of terminologies and structures, which are transferable from discipline to discipline, and gradually you can take advantage of the existing materials in your brain and get into unknown fields with less pain.
Studying outside of this structure is certainly doable, but then all your knowledge structures would be based on personal expressions, then it would be harder to transfer the skills and knowledge. But transferability is always naturally ongoing, and that is why a lot of very old wise people would tell you a story of them doing something completely random when they were young and they’d use that wisdom for every other aspects of their lives.
I definitely find it a lot easier to do inter-disciplinary study at the university than in workplace, in the street or in socializing. Because outside of the institution, all wisdoms and knowledge are expressed in their own ways, so the merging process can only happen in brain in a more abstract manner. Sometimes you know that you are employing your skills from another field to benefit your action in another, but you cannot make it clear what that is exactly.
The thing that is the most transferable in my humble opinion is music, and I learned more from it about stuff I study in academia than anything else. Any music, rock, classic, popular, rap, techno. It teaches me patterns, and the responsibility of academics is to find patterns, or assume patterns and prove them right or wrong. Music teaches me both science and humanities. It also teaches me to acknowledge my humbleness and at the same time take advantage of my limited cognitive ability.
Academia is a process of baptizing phenomenons and giving them names. Names are keys to dictionaries: they evoke something much larger than a simple word, so that you store and converse in a more concise manner. After baptizing, they are dictated into existence, they are cognitively created, and now they have a nature, which is the nature of how we understand it.
This is a process of mapping the world with language. Once that happens, you can play around with the language and make magical things happen.