Whow, i think you're the first person i've heard of to actually test that theory. We don't even mention it (although some newcommers do question this) coz we all assumed you'd have to wash down the tablet with a lot of grapefruit juice, and all this just before bed..Cocoa, that makes sense, maybe a spot of brandy, but not a lot of people have grapefruit nightcaps.
Do you have muscle pains?
Unless your doctor has said otherwise i shouldn't worry too much, i'm not sure how long it takes simvastatin to leave your system (but i think it's sort of 6 hours, which is short for a statin) or what dose you were on. But i've done some research and what happens is a chemical in the grapefruit prevents the liver from breaking down the statin so it hangs around in your body for longer. I'm also not sure if you have to be a regular grapefruit drinker to really mess up, ie the statin levels build up over time so you'd have to be washing your pills down with juice for weeks perhaps? I dunno. You can probably still enjoy grapefruit juice in moderation.
As for me, the only thing i'm likely to do with my simvastatin is forget to take it.