You are a product of how you process and interact with your environment.

Be alert, situationally aware.

Process actively, notice and distill patterns.

Try things. Push the environment.

Which also reminds me of "You are the average of the few people you interact the most with".

I don't think it's quite that close. There is still a distinction between being a product of your environment and being influenced by your environment.

My HS college prep English teacher, who was one of the best teachers I ever had, put it this way: "Garbage in, garbage out." His point was that it simply isn't rational to believe that you can read nothing but National Lampoon, Mad Magazine, or the county newspaper and become a great writer. You have to read, digest, and breathe the air of the great works of fiction and literature and allow it to do its work in influencing your prose style, cadence, and structure.