When scientists clone a gene, they isolate and make exact copies of just one of an organism's genes. Cloning a gene usually involves copying the DNA sequence of that gene into a smaller, more easily manipulated piece of DNA, such as a plasmid. This process makes it easier to study the function of the individual gene in the laboratory.
To me a deep thinker is someone who is an innately curious, and deeply insightful. He/she has a profound understanding of the right questions to ask in the face of both reality and the unknown. He/she is not afraid to see reality and what is there before him/her.
This automatically makes it harder for you to understand something deep because you started thinking on that concept with the idea (in the back of your head) that you cannot do it. Geniuses never think of something as being hard, rather they allow themselves to believe that if they try they will be able to understand that concept.