Surrounding yourself with negativity = a negative thought life.
Several months ago, I was immersing myself in the misery of others, and doing little to rest and recover and strengthen myself spiritually. (I didn't realize what was going on at the time.) What did I expect to come from that sort of environment? Happy thoughts? Oops.
Practical example: if I were to fill my bathtub up with manure and slide on in, would I come out clean as a whistle?
I'd come out with poop clinging to my body. It'd take more than a couple of rinses to rid me of the filth, and the stench!
On the other hand, if I immerse myself in GOOD things—in God—I will radiate HIM. Over time, I will become more and more like Him!
Do not be misled: “Bad company corrupts good character.” - 1 Corinthians 15:33