I know that seems contradictory--real life not seem believable? But how many times have you read something that seemed out of character, wrong or self-indulgent--or worse yet, Mary Sue-ish? I'd say it's because one or more of these rules is broken:
1. You gave your character your reactions, not his.
2. You didn't change the details enough to fit the story you are writing.
3. The event itself doesn't fit the scene you're writing. (i.e., just because it's a cool or touching event or is a personal catharsis to write does not mean it belongs in the story.)
4. You failed to give the event significance in the story (perhaps because you are still giving its significance to your life)
in other words
5. You failed to take yourself out of the event and put your character in.
This week, I got to put in two events from my past into my story. The first was a frustrating time my Freshman year of college wheen I'd been studying (or trying to). I'd read over the same page of statistics about five times, trying to memorize and feeling rather martyrlike about it, when a guy from my brother floor yanked the book out of my hand and challenged me to tell him what I'd just read. I couldn't. Not even the subject of the section. I was so mad I wanted to cry. He suggested I take a break.
The plebes from Zombie Death Extreme are boning up for their certification test. Gordon is the ex-Marine who is not the sharpest tool in the shed. So I thought he could use a moment like this.
Of course, I had to change the setting to fit a mid-twenties male adult hoping to pass a career test and maybe win a million dollars while he was at it. The people around him are the competition. So: no dorm, no statistics book, no martyrlike feelings. He would not get upset like I did--slug or slow burn is more Gordon's style.
Here's how it played out: Gordon is about to take a study break when Roscoe and Nasir show up at his apartment.
Roscoe was looking at the beer in his hand. "Please tell me you aren't intending to get drunk alone. On that."
"I'm studying," he growled. "Been studying all day. This is my first, if you must know."
"No, it's not." Roscoe brushed past him, snatching the beer from his hands and putting it back into the refrigerator. Only when Nasir followed did Gordon realize he'd been hanging out in the hallway. Have to work on that situational awareness.
"I refuse to let you waste your evening on swill," Roscoe said. "Go put on something presentable. Something that says, 'chick magnet.'" Pawing through his refrigerator with one hand, Roscoe waved in Gordon's general direction with the other.
"What? I'm studying."
"Yeah? Tell me the last three things you read."
Gordon paused, his mind blank. "I hate you."
Did I think about the rules as I wrote? No, I was too busy thinking about Gordon--but then again, that's the key, isn't it?