One of my greatest strengths is my ability to focus on a specific task and get it done. It's a laser-like focus that blocks out everything around me. It's awesome. But it's also one of my weaknesses. I tend to apply laser-like focus to a specific problem or fear, and within minutes, I can go from happy to suicidal. Like...what's that about?
I certainly don't claim to be a scientist, but I have learned that your mind acts as a magnifying glass. Whatever you choose to focus upon, it becomes bigger. Just like a magnifying glass on a summer afternoon, if you focus the lens for an extended time, you can start a fire.
If I focus on my sobriety, I become useful to others. If I focus on my problems (financial insecurity, resentments, doubts and fears, body image, loneliness, being overwhelmed at work, etc.), I become incredibly miserable.
Every day presents a choice: I can choose to focus on the problem, or I can focus on the solution (which, for me, is God).
"Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable--if anything is excellent or praiseworthy--think about such things." Philippians 4:8
If you're looking for some extra inspiration, here's an amazing publication titled, "As A Man Thinketh", written by James Allen in 1903. It's incredible.