As a result of my illness I missed the chance to shake my butt at the boss.
See, there was a kindergarden presentation I was supposed to be at on Saturday. I was busy being sick, sore and sleepy, so I couldn't go. And the kids, along with my colleagues, did the hokey pokey. They put their bottoms in, they put their bottoms out, they put their bottoms in and they shook them all about. Including at the Superintendant. I can't believe I missed the chance. I mean, how often can you shake your butt at your boss without consequence?
While I was sick, I totally did not remember anything about the hokey pokey. I didn't remember until my colleague reminded me. Then I was kind of pissed because my stupid stomach had affected all of these things. My hands still hurt from the drip. My joints were sore for some reason unbeknownst to me. And now, I'd missed shaking my butt. None of these things were a given seeing as the problem started with my stomach.
Lots of things in life are like this. Threads are woven and connect to other points in unexpected ways. When we write, we have to think about these threads. Let's say you write a hearing-impaired teen MC. How does that connect to other points?
On the most obvious level, she has trouble hearing. She has to ask her friends to repeat things. What happens when we get a little less obvious? Maybe she likes concerts, because the music is way up loud and easy to hear, and all her friends have just as much difficulty deciphering one anothers words over the din as she normally does.
What happens when we follow this thread all the way out to the least obvious ends? Well, this is a teen, right? So she may be self-conscious. Maybe she doesn't like people to see her hearing aid and so she always wears her hair down. Maybe she hates the beach, because she either has to take out her hearing aid to swim, or keep the ability to hear and just sit on the sand.
Of course, there are cautions. Take care not to follow this thread out to ends which don't connect. In other words, there are some things that are not affected at all. There's no reason a hearing impairment would affect a love of art. To extend this point further, it's a mistake to think that your big important concept HAS to affect everything in the main character's life.
Also, be careful of assuming that some ends are mandatory when they're not. We've all seen the "flaming gay." I know he exists. I've met him. Does that mean that every gay is a flaming gay? Certainly not. There are uber-manly gays. And gays who are feminine in a more-girly-less-faaaaabulous sort of way.
Finally, remember that you are the God of the universe in your book. You need to know how the threads connect and all the places those threads weave into. Your readers don't need to know. In fact, not knowing some of the threads can make it feel more real. After all, we can only partially explain the actions of people we know in real life, selves included.