[thecage411]

I asked an anesthesiologist this question and am transcribing from memory (hehe), so I may have screwed some things up.

The answer to your question in is no, you aren't suffering enduring horrible pain while under general anesthesia. That doesn't mean you won't experience things you would rather not remember. Some examples: 1) patient may experience burning sensation from propofol (induction agent) entering the body 2) patient may see something disturbing before general has kicked in (e.g. a big saw before an orthopedic procedure) 3) in certain cases (e.g. emergencies) or due to human error, patient may not be fully under pre-surgery, e.g. patient may remember breathing tube being inserted.

The high level answer for why you are given midazolam (at least in the US) is because anesthesia is a "patient satisfaction" service and giving it increases patient satisfaction.