80% of thoughts the human brain processes per day are negative. It simply means that a human has an 80% chance to destroy him/herself every day

you have said it right! this is something we do unconsciously and need to pay attention to our thoughts.
Instead of paying attention to all the negativity which surrounds us and all the things we don't have. we need to pay attention to all those things Allah has blessed us with and be grateful always for all that we have.