Every person have their own way of learning, for each one of us there is a method that works better. We have to try and understand the differences and that another person may be slower/faster to learn using a particular method. It is good to know which method works better for you, it may be a combination of several, it may be something completely different that I couldn’t possibly have thought of. I have met people that cannot learn without sitting down and studying by themselves. I have met people that cannot learn by sitting down and studying because they just can’t focus that way.
The ancient exercise of reading may be the most common and direct way of learning from others, someone who knew a ton of the subject you’re studying wrote all about it, you read it, you try to absorb as much as you can. There are some ways of optimizing this. When we are at school we’re forced to solve and deliver exercises in form of homework, it helps to fixate the knowledge we just read about. Another way that could be more fun for some is by reading in a group then discussing about the book, it is amazing to see how different people process information in different ways.
What about when you don’t have the time to read an entire book about something, or if it is something small enough that could not be very adequate to be in a book altogether. You can read a blog post about it, an article. Some may prefer watching a tutorial in a screencast form, or on a presentation. Listening to another experienced person talk about something may be more engaging for some people that don’t find the same excitement on reading.
And what if there are not many resources available, maybe you’re trying to learn about a new thing, let’s say a new framework that is still not very good on documentation. You can experiment, you can explore, if it’s an open source software project you may also want to read the source. Once you figure it out, write about it.
Most people I’ve worked/studied with found that teaching is the most effective way of learning. When you’re teaching you have to take the time to really, really think about the subject and make sure that you know it. It may be ok to get something wrong for yourself, but you don’t want to be the one to be blamed if more people get it wrong. So writing about something you just learned may be a very effective way of learning it for real.
You can also learn a huge deal of knowledge by pairing together with another human being. One of the reasons we pair is to make knowledge transfer a more natural consequence of our work rather than an obligation. And since you are with another person you are going to be extra motivated to learn/teach it correctly the first time.