There are many things people learn, and many reasons they learn them.
Almost everyone learns at least some things because they have to. Like reading, writing, and basic maths. It's hard to imagine a modern society where children are offerred the choice of opting out of learning these elementary skills. Most people choose to learn at least one or two things because they want to. Even if not for the pursuit of excellence, people still learn golf for the fun of it.
These two categories, have's and want's, aren't always interchangeable. There are countless people in the world that learn maths because they want to, but it's hard to imagine anyone learning golf because they have to (except perhaps the children of once-famous golfers who, in spite all the efforts of their successful parents, refuse to follow in their footsteps).
But there is one thing that all skills have in common, one thing that makes a skill a skill. To be a skill, a thing must be able to be learned. A skill is not some inate behavoir like breathing or sleeping. To be learned, a thing must represent the discovery of some previously mysterious information that not everybody has.
And whatever the motiviation, people achieve proficiency in skills to different degrees. Not everyone that decides to learn golf wins The Masters. Some people try much harder to learn skills for much longer only to never reach the same level of proficiency as someone who spent significantly less time and effort than them.
A common explanation of this is talent. A pre-disposition to proficiency in a particular skill. In physical skills like sports, this is often synonymous with genetics. In golf, a tensile frame suited to explosive strength and long levers (arms) are often leading indicators of proficiency. In more mental skills like maths, logic and reasoning are often signs of future appitude.
But I think by far the most accurate sign of future proficiency in just about any skill, physical or mental, is the ability to learn effectively. Anyone whose coached or mentored someone for any length of time knows that no matter their talent, it's very difficult to teach anyone without great focus and attention to detail, things that come with being a good learner.
But learning itself shares all the same properties as a skill. It is not innate, people who are good at it share a common set of attributes, and some people are born with a more natural proficiency for it than others. The special thing about the skill of learning though, that sets it apart from all other skills, is that once learned it makes it much easier to learn everything else.
Anyone that's played any kind of world-building strategy game will recognise this paradigm as similar to the most optimal way to complete them. In these games your objective is to upgrade your world to the highest level where each level cost more and more currency to unlock. The fastest way to complete these kinds of games would be to avoid the distraction of all the possible features you might want to add to your world and first build a way to scale currency generation. Once scale is achieved in currency generation, it would take a matter of minutes to complete the game.
This is similar to the idea of learning skills. By not getting distracted by all the possible skills you want to learn or things you want to achieve, if you first focus on becoming good at learning, you'll most likely become proficient in the thing you originally wanted faster than if you'd focused on it straight away.
So then how do you become really good at learning? As someone whose had a keen interest in learning a number of things, and now considers himself fairly proficient in learning something new, I can suggest some patterns i've noticed.
For physical skills, the best path to proficiency is often mimicing. Learning to swing a golf club the same way as Rory McIlroy, while likely not achieving the same level of skill by way of talent, will most likely get you to your natural limit pretty fast. And being good at mimicing is largely dependant on an ability to observe effectively, and produce the same output as what you observed. Watching videos of how professional golfers swing, trying to imagine what forces they might be feeling on their body, and then trying to create those same forces yourself will probably lead you to a better result than just 'giving it a go'.
If the pursuit is more mental, then imagination is often more important in learning effectively. Being able to not just hear or read how a concept is described and taking it at face value, but being able to draw connections to what you already know, and to imagine your own ways of thinking about it.
But those two examples largely describe the same core learning loop: being able to recognise evidence of proficiency, efficiently injest the relevant data about that evidence that is the most likely root of the proficiency, indexing that data for yourself by creating your own context, being able to translate it an effective output, and finally being able to effectively update your context with each repitition.
I don't think that people really think all that when they do try and learn a skill. But I do think that being aware of what's actually going on, 'behind the scenes' if you will, and conciously working with the process does often lead to a better, deeper understanding of a skill often in a shorter time period.
This is often evidenced by a strong correlation between the difficulty of a skill, and the level of proficiency in that skill that those who are good at learning are able to achieve in a set period of time. Often the more difficult a thing is to learn, the further ahead those that are able to apply learning theory will be than those that just go in blind.
If you were to ask someone who has achieved deep proficiency of any skill to stop what they are doing and learn a new unrelated skill, I would put money on them being better at that skill than the average person after 6 months. Assuming that there is no talent delta, then what remains as the difference? It's their experience of, and therefore ability to, learn.
So next time you want to learn something new, maybe take a second to consider if you fully understand what you're getting yourself into before getting started.