As our skin absorbs the sun rays so likewise we need to absorb the rays of knowledge & wisdom not just through reading, but through reflecting (meditating, contemplating) on what we read. Although physical tans can be hurried through various means, acquiring a luxurious spiritual tan takes time because it takes years for our brain to start making inter-relational connections with the things we read. In time, things we are currently reading in the Bible, will start to call back to our minds things we've read in the past.
That is one reason that associating with like-minded believers is so helpful. Listening to them express their faith helps us make new connections in the way we think and reflect on scripture. Learning from other's experience accelerates the learning process BECAUSE what may have taken us years to conclude now can be learned much quicker from others that have done this longer. After more than 40 years of studying the Bible, I can still very humbly admit that many of the new thought-connections I make are because of hearing the perspective of fellow believers. Indeed, more than few of the articles I've written here were because of a comment I heard that I expanded on.
So if you admire the deep spiritual tan (knowledge and insight) that others have, know that you can have it too. All you need to do is study, reflect, and associate with fellow believers.