we have far less control than we like to think

From The Emotional Brain (1996) (bolds mine):

One of the biggest surprises from LeDoux's work is that there may be no such thing as the limbic system -- a brain structure that has been supposed to underlie emotion and motivation. All students are taught about the limbic system, LeDoux said, "but in my opinion, it's no longer a valid concept."

[...]in 1974 and 1975, experiments carried out on so-called split brains attracted his attention. In people who had had the connection between the left and right brain hemispheres severed, the left side often did not know what the right side was doing. But emotional information seemed to be leaking across the hemispheres, suggesting a different sort of wiring than for language or movement.

He said that at the time cognitive scientists tended to confuse emotions and feelings. LeDoux says that emotions are hard-wired, biological functions of the nervous system that evolved to help animals survive in hostile environments and procreate. The emotional systems underlying fearful, sexual or feeding behaviors are pretty similar across species, though each emotion may have its own separate neural wiring.

Feelings, in LeDoux's scheme of things, are "red herrings," products of the conscious mind, labels we give to unconscious emotions. "What we really want to study is the brain system that generates emotions," LeDoux said, not the higher brain systems that read meaning into them. Because many researchers thought they first had to understand consciousness and feelings, he said, they were intimidated and stayed away from emotions.

One of the biggest surprises from LeDoux's work is that there may be no such thing as the limbic system -- a brain structure that has been supposed to underlie emotion and motivation. All students are taught about the limbic system, LeDoux said, "but in my opinion, it's no longer a valid concept."
[...]
On closer examination, LeDoux found that the amygdala is designed to detect predators. For example, when rats are threatened, they emit very high frequency (20,000 to 30,000 cycles per second) screams. When another rat hears this scream, a signal goes from the auditory cortex, where sounds are processed, directly to the amygdala. In other words, says LeDoux, when these sound waves penetrate the rat brain, the amygdala is instantly activated even though it does not "know" the sound is coming from another rat.

The human brain is similarly wired, LeDoux said. A visual stimulus, perhaps the sight of a snake on a dirt path, will travel to the amygdala in a few thousandths of a second. The human amygdala contains cells that fire in response to expressions on faces and may also react to objects of fear.

But, LeDoux said, the amygdala is specialized for reacting to stimuli and triggering a physiological response, a process that he would describe as the "emotion" of fear. That is distinct from a conscious feeling of fear, LeDoux said. Feelings, he said, arise from a second, slower pathway that travels from the ear to the amygdala and then on to the higher cortex. There, the frightening stimulus is analyzed in detail, using information from many parts of the brain, and a message is sent back down to the amygdala.

If the message is a false alarm -- hey, it is a stick and not a snake -- the cortex will try to abort the amygdala's alarm signals. But the person will have felt a jolt because of the initial arousal of the amygdala.

This double pathway is very different from the limbic system that is taught to every biology student, LeDoux said. The limbic system is a hypothetical construct of pathways in the forebrain, which contains the hippocampus, amygdala and a few other tiny structures, that supposedly gets all sorts of sensory input from the external world -- sight, smell, hearing, touch and taste -- as well as from the viscera. When these sensations are integrated in the limbic system, emotional experiences occur.

Such double wiring can create problems for people, LeDoux said. Neural connections from the cortex down to the amygdala are less well developed than are connections from the amygdala back up to the cortex. Thus,

the amygdala exerts a greater influence on the cortex than vice versa.

Once an emotion is turned on, it is difficult for the cortex to turn it off.