The reality that you experience is a by-product of the thoughts that you think. Thoughts are information, or psycho-emotional impressions that over time imprint themselves upon the subconscious mind.
If thoughts are seeds, your conscious mind is the top-soil whereas the subconscious is all that is underneath. The origin of a thought could be likened to dropping the seed on top of the soil. Over time, the seed begins to sprout roots, and as it is watered and nurtured, the roots spread deep beneath the ground and into the subconscious mind.
The most frequently experienced and practiced psycho-emotional impressions become deep-seated core beliefs. These are often rooted by intense, traumatic experiences that happened during childhood. The vibrational signature of that experience created a recurring reflection in your external reality, which reflects your thoughts back to you.
Even more impactful than individual traumatic experiences were the constant impressions being made upon you by your family and the environment that you grew up in. You could think of these as the seeds that got the most water, sunlight and nutrients. Although the sustenance itself, in this case, is the attention and focus of your consciousness.
“Where attention goes, energy flows...and something grows.”
The more attention is focused upon a thought, the more energy it is fed, and the more it grows. This is the case regardless of the nature of the thought: whether it be positive, negative, or anywhere in between. It will begin to express itself in manifested reality in increasingly prominent ways.
Attention equals intention, and your intention is what your life becomes. There is not a force in this Universe more powerful than conscious intention. Remember that.