Philosophy is not a 'thing' called science. 'It' doesn't contain patterns and principles. 'It' is not “too broad a subject for any one person to claim understanding”. You (collective 'you') treat philosophy as if it is a 'thing' to understand and you're right! Philosophy is the 'container' that holds all of your pre-existing conclusions, your pre-suppositions, and your concepts about what happens between the beginning and the end of 'philosophizing'. Your pre-existing conclusions, your pre-suppositions, and your concepts about philosophy is not philosophizing. It is kind of like the relationship between 'life' and 'living'. 'Life' is the container and 'living' is the content. 'Life' is empty and meaningless, 'living' is where the good stuff is. You're re-presentation of someone's 'life' in book or a book report is a gross injustice to the person who did the 'living' and it is always a mis-representation.
It is the same with what you call 'philosophy'. Books and reporting about the philosopher's philosophizing are empty and meaningless unless you are philosophizing. You have to step out of your subject/object world and become the conversation that is contained in the book. By 'becoming the conversation' you will sacrifice your pre-existing conclusions, your presuppositions, and your concepts.
The reason philosophy is “too broad a subject for any one person to claim understanding” is because the way it is taught and the way you read it is the culprit. When you start off on the wrong path you've already committed your 'self' to the wrong destination.
The way it really happens is that you (even as you are reading this) are Be-ing (living). You are the conversation contained in the book. Instead of taking animal rationale, res extensa, and cogito sum for granted and trying to understand them you realize that for example, cogito has gotten all the attention and the sum has been ignored. (The reason the sum has been ignored is because the 'sum' can't be contained in the measurability and definability of the world.)
As you pick at the 'threads' of concepts that make up 'philosophy' you begin to see through the pre-existing conclusions, the presuppositions, and the concepts that have been forced upon you by the 'world' and the 'they'. You discover that 'living' is not a combination of characteristics called 'life' and 'philosophizing' is not a combination of characteristics called 'philosophy'.
The source of the contents of the container called 'philosophy' is you, who you really are, Be-ing. It is not the other way around. Philosophy is not some 'concept' (thing) out there for you to understand and then, when you're done, hopefully you can accumulate everything you've learned and then know the answer to “Who Am I?”.
Humans Be-ing have been trying to do that since way before Parmenides. You'd think that after several thousand years we would have put 2 & 2 together. Alan Watts said that we “haven't graduated past 'territorial monkey”. We are still defending the same territory defined several thousand years ago and making sure we keep the other monkeys out, no matter what. (I'm howling like a monkey, I just can't put on the page.)
As you de-construct your pre-existing conclusions and presuppositions you disentangle your 'self' from the measurabilty and definability (thingdom) of 'philosophy', the 'world', and the 'they'. You come to a point where you realize that the conclusions, the presuppositions, and the 'concepts' in philosophy are distractions and can no longer be used to prove the existence of your 'self' (Be-ing). When you come face-to-face with the emptiness of the concepts you reach a point in your thinking called (by Heidegger), the "possibility of the impossibility of your existence" who you've been Be-ing dies so that you can be your 'self'. You uncover/discover that the theories, the conjecture, and 'the ability to explain' your 'self' has nothing to do with Be-ing your 'self'. This is the essence of human freedom. In Be-ing you answer the question "Who am I?"
This is what is called 'transformation'.
When you make the 'leap' from the measurabilty and definability of your pre-existing conclusions and presuppositions into Be-ing you do understand it all and 'philosophizing' becomes an adventure and not a entanglement like 'philosophy'.