I do. We tend to notice the things we focus on. I know for myself, when I’m in a negative mood or thinking negatively, I notice a lot more negative things than positive things around me. When I’m in a positive mood or thinking positively, it’s the opposite. I’ve also noticed that when I’m in a negative mood, I am more closed off to the things/opportunities around me. When I’m in a positive mood, I’m more open to the things around me and more approachable to the people around me.
It also goes along with the saying, “if you think you can’t, you can’t”. Some people can be very self-limiting. When we doubt ourselves, we are more likely to second guess our options and not push as hard to get something done.
As with everything, there are always people that are opposite of this and do better when they feel like they working against the odds.