Guilty.
You hear quick footsteps and think that is a molerat.
You think that using a cap will improve your perception skills and make you better with explosives,and you try to remove an frag mine with your bare hands with fear that it will cripple your legs.
I'm guilty of the footsteps thing. I'll be walking somewhere, like in a stairwell, and there'll be the echo of my footsteps, and it sounds just like it does in Fallout when you're walking up or down stairs. So weird.
You know you're playing too much Fallout 3 when you have these sudden urges to just walk in some random direction in the countryside hoping that you'll "perceive" enemies in the distance so you can drop onto one knee and go into sneak mode, pull out your sniper rifle, and blow them away at 100 yards.