I know what you mean
Around the time I was afraid of balloons I was afraid of tornadoes. Whenever there was a storm I'd sit in the living room and watch the Weather Channel non-stop. If the storm got really bad I'd get pretty hysterical...then I read about invisible tornadoes, and how it can be a totally nice day...and well, that was bad...
I'm not afraid like I was when I was seven, but when I'm asleep and it storms I wake up and find myself scared :P
...must be some weird subconcious thing...
I don't like rollercoasters either o_o