This is true, XX, but the answer is more complicated than this.
The first and most important thing to do, is to blend completely with the hurt. Be like a swimmer who finds a warm current and decides to very carefully centre their whole body in it, not for instance, just the foot that first contacted it. Swimmers carefully arrange themselves into the warm stream, slowly, slowly, slowly, until every part of the body is bathed in the warmth.
Now hurt is like that. I slowly arrange myself into blending with this triggered pain until it and are one. Then, I stay there, opening, opening myself to it slowly, slowly. When this congruence is achieved, I hold it as long as the energy flows. If I do nothing more than this, the pain will dissipate.
But there is more that can be done. One can allow a memory to appear from within the pain, and soak in the pain and the memory both at the same time, seeing how the pain was originally generated, and how it repeats each time I am hurt. This does not mean that the present pain is not real; it just shows the psychogenic overlay of old hurt on the new.
I could go even further and speak some short words or phrases that can mirror or carry the hurt. Thus, I allow it to combine with my cerebral symbolizing functions, and then in addition this promotes the pain reduction through activating the conscious muscular systems of the body's vocal chords. Also, this making of words and sounds allows the brain to hear externally, what it, up to now, has only heard internally. This not only neutralizes tension within, but sends that tension outwards and away from its bound and hidden internal forms.
I could use this pain to show me what it means to be a biological organism and how we suffer from that simple fact.
I could go even further and use the pain to conduct a search for the meaning of pain in our existence to try and find if, in fact, there is any.
As long as the pain is active in me, it will drive my searches deeper and deeper, wider and wider and my over all consciousness will increase year by year as I continue this process.
Feeling and body oriented inner searches are so much richer than the pablum brigade would have us believe.
Their beloved warm soup of infantile experience misses the whole great point, the power the depth and the breadth, and in short, the full potential of the feeling and body-oriented search.
It is the therapist's inability to face the abyss/the void/the nothingness, and their ultimate impotence, that causes them, in their search for power through ego centered knowing and the seeming control that it brings, to glom on to the "safe" points of infantile trauma, where they seduce themselves and their clients with the "safety" of their knowledge.
In this way Primal becomes the new religion. It also becomes the new defense.
Paul Vereshack

Another factor to consider is the possible similarity of the specific emotional contents of the two feelings. Its more complicated than that, but the feeling components of our past repressed and even unrepressed hurtful emotions are stored according to their feeling content (rejection, guilt, etc.). When a hurt is felt, our brain is scanned so that we will know how to react to the experience. My guess is that perhaps both of the feelings in question had a similar emotional content even if we are not always conscious of this. When we travel down to the earlier experience and work on it, we are really also working on the more recently triggered feeling because of that shared similarity of content.
That's one reason why we don't have to reengage each and every incident of hurt. For example: the general relived feeling of "Please Like Me Momma" can cover and resolve a number of incidents when our mother's love was imperative, Similarly, each incident of early chronic sexual abuse does not need to be relived.

--John A. Speyrer, Webmeister, The Primal Psychotherapy Page