Our sensitivities are indicators of our inner projections... the thoughts or beliefs that we hold to be true. The indicators are critical to pay attention to.
I'll give you an example...
I go shopping and pick up 4 bags of groceries and bring them home. As my loving wife is helping me unload the groceries, she notices that I've forgotten an item, say, eggs. She point this out to me in an observational manner, "you forgot the eggs".
On a good day...
I hear the "observation". I don't take it personally nor do I feel threatened by the comment. It's simply a comment... information. I may respond with "do we need them today?" or "would you like me to get some later?"...
On not a good day.... (I'll describe later what this means)
I hear the comment and take it personally as a negative judgment and feel hurt and defensive. I quickly go through a cycle of self-comments, most of the time I am not aware I am doing this...
My self-comments will regarding assumptions of what I think she's really thinking... I always forget things, I can't shop properly, I can't do anything properly, I can't be trusted, I'm inadequate, I'm incompetent, .... and on and on... until the inevitable ending comment... I know you hate me! or I know you don't want to be with me!...
I know, I know, ridiculous thoughts, unfounded in reality. So where then, do they come from? What makes them seem so real?
They exist in our minds as a reality that we are convinced of at the time.
Our minds are that powerful that we can make a non-reality, a reality.
These thoughts exist because they are a belief that we hold to be true about ourselves. Beliefs that we do not want to recognize because to do so feels counterproductive, bordering on psychosis. However, the belief must be there and is seen as a sensitivity that we react to.
Which is why it's so important to pay attention to them when they occur.
We don't immediately recognize them as sensitvities because we're busy being defensive, irritated, angry and blaming.
As important as it is, it's not an easy nor comfortable process to work through. If you find yourself in a similar situation, try to catch yourself or at least to remember the situation and the inner thoughts and feelings you may have been experiencing. I'd suggest writing the situation and responding feelings down first and then having a look at them later.
It's often very helpful to work with someone else not as invested in the situation to help you work through the process. Talk to a counsellor who is willing to explore the indicators until you're more comfortable doing this yourself.