Reason Graph
In life, we have things we want and certain truths about ourselves (e.g., I want to become rich or I like being productive). Under these statements, there's a layer behind that can be revealed when you ask the question "why?" (e.g., why do I want to become rich, or why do I like being productive).
But if you continuously think via this hierarchical or stack-ish structure, you have to choose a conclusion: you eventually reach primitive/level 1 truths, there are infinite layers to unlock, or the reasoning structure is flat.
I don't think there are infinite layers to unravel. Not everything has deeper meanings to be explored. For example, liking pizza. I just like pizza. No deep plot line or explanation needed.
Although this is a very plain example, when you continuously ask "why" about any of your other values, you always eventually get to the point where you do things just because you want to, and that's just how you are currently wired (this is not fixed, though).
My conclusion is a mix of primitive truths and a flat structure, illustrated similarly to the graphs shown when studying gradient descent:
In this interpretation, each vertex represents an event/reason, and the deeper the vertex is, the more impactful the event/reason is on your everyday actions or thinking. The depth at which certain events are in someone's graph is entirely arbitrary and up to how much importance the person has in it.
Even a reason as simple and seemingly dull as "I like cars just because I think it's cool" can be extremely deep in one's graph if they choose to.
The driver behind depth is not complexity but rather identity alignment. The difference between "I like pizza because it's good" and "I like programming because it's cool" may simply be that I identify more as a programmer than a pizza lover, so that holds more weight in my conviction.