It all started when she was a little girl. Shes not entirely sure who she learned it from - if anyone - or if she figured it out on her own. She's not even entirely sure at what age the whole thing started, but if she had to guess, it would be around the age of four. Maybe five. What she does know is that it helps her.
Back then, it helped her fall asleep when outside forces seemed intent upon keeping her from meeting slumber. Sometimes, it was the looming threat of a monster, waiting for the opportune moment to strike. Sometimes it was the neighbor's cat, constantly wailing some high-pitched lament that could only be understood by other feline creatures. Sometimes, and more often than not, it was the elevated voices of her parents, always trying to outdo the other. Insults that she couldn't quite understand (her mind was still untainted, you see) hurdled on the sound waves of her father's voice. Scoffs of disbelief or insults she understood a little better (but not in relation to her father) came shooting back from her mother's mouth. Hours would go by. Hours that she was supposed to be asleep (they didn't tuck her in or read her bedtime stories anymore). Didn't they realize that their arguing was certainly not conducive to a little girl's beauty sleep?
But that's when it all started. Somehow, her small, plump thumb had found its way into her tiny mouth. Suddenly, she felt comfort. Let those silly adults yell all they want. Let the monsters under her bed and in her closet attack some other child. She wasn't scared anymore. Sleeping was suddenly within an arm's - or in this case, a thumb's - reach.
But most kids outgrow this habit. Moat kids become teenagers who develop defense mechanisms (like apathy) when mom and dad are fighting - again. Not her. She was too naive (or perhaps too trusting, or perhaps too simplistic) to create for herself a hardened, jaded shell. She kept her proverbial security blanket wrapped up in her thumb.
This makes it difficult for her in her day-to-day life. After her sister's fatal car crash on a local highway (she was sneaking out one night to see her boyfriend that no one approved of), she finds her blood pressure and heart beat spike when she's forced to take one of these deathtrap roads. "Killer speedways" she calls them.
Her finger - not as small as it has once been - again finds its way to her not-so-tiny mouth (crusted with the $0.99 lipstick she received as a gift) until it slides inside, soothed by the feeling of her wriggling tongue against the fleshy pad of her finger.
She forgets that other people can see her as she does this. But she doesn't care. She's already running late, and there's so much work to get done.