It had been another day of worrying.
It had been another day of planning.
The list of things to be worried about and thought about was endless. Just keeping up took much of that effort. There were bills that needed to be paid, which meant stamps had to be found somewhere. His shoes' laces had frayed, necessitating a trip to the drug store to buy another pair of shoe laces. The weather had been hot the past week, meaning he was sweating and uncomfortable all the time, which meant he had to do his laundry twice as often, which meant he had to go to the bank for quarters. And while he was doing the laundry, he should try to take out the garbage.
This was the first layer of thought, the endless details of life that had to be dealt with just to keep his head above water.
Then on top of that was the constant thinking of ways to "get ahead". He wasn't a social climber, as such, but he certainly didn't want to be stuck in a dead end job answering phone calls from angry bank customers for the rest of his life. He didn't want to be uneducated and living in a shitty city with a bunch of friends whose idea of fun was drinking cheap beer while watching football, or smoking shitty weed while watching cartoons. And of course, he didn't want to be alone forever.
So his mind was full of constant plans of things he could do to, things that he could do to escape the drudgery of life. Since he was too busy treading water, he could hardly ever act on any of his plans. Which meant that he had to spend even more time thinking of hundreds of plans for getting ahead.
Although all the other matters were important, the thing that most obsessed his brain was women. He lived in a big city and had a pretty active social life, so he was meeting new women all the time. And everyone he met, he got a little crush on, and studied and calculated intently to see what chance she was interested at all. He usually managed to convince himself that there was some interest being returned, and then was always disappointed when it wasn't, and then returned to more plotting and thinking.