My cholesterol dropped!

This is very wierd. Here is my history:

I have been taking 5mg/daily of Simvastatin for 5 years now. The pills come in 10mg size and I cut them in half. Over the past 5 years my numbers based on quarterly blood tests have ranged as follows:

Cholesterol: 192-246 (avg 206)
Triglycerides: 73-140 (avg 89)
HDL: 51-66 (avg 56)
LDL: 101-163 (avg 133)

Basically, pretty much what I would expect. Nothing too high and just the triclycerides are fine.

Today my blood test numbers are:

Cholesterol: 135
Triglycerides: 38
HDL: 40
LDL: 88

So what changed? No change in diet. Slight change in exercise - less exercise over the past 3 months.

Yesterday I was at a plastic surgeon to remove two small pimples from my face and head. He used a locally injected anesthetic on my head and since then I have taken a total of 4 Advils. Blood test was 22 hours after minor surgery and 8 hours after last Advil. That is the only thing I can think of that would affect something.

So to all the experts on the forum - what magical cholesterol cure is my body going through?

Thanks!