> children sometimes wake up from anesthesia with a set of side effects including lack of eye contact, inconsolability, unawareness of surroundings, restlessness, and non-purposeful movements
In general, a very simple mental model for general anesthesia is that it's an unnatural state for your body and your body will do its best to get rid of it, similar to say alcohol or drugs. This means systemic inflammation, stress on your cardiovascular system, liver and kidneys, brain, and so forth. Most all of these issues scale with how much anesthetic you receive, similar to a hangover being worse the more you drink.
In other words, general anesthesia is rough on you just like getting black out drunk is, it's just more controlled and we do our best to try and limit the downsides because it's invaluable for surgery where applicable.