What we can't see or find in ourselves we will unconsciously seek in others.  That one kind of sounds weird but it is true and is quite similar to the expression "...opposites attract...".  From around the time we come into this world, and as we continue, we feel that there is something or many things that are missing in our lives, the Core Wound has already been mentioned and essentially we can say there are Gaps.  Our first thoughts will be that we need to fill the gaps with somethings, this would be logical, but what we don't see easily is that we are supposed to fill the gaps internally, not fill the gaps with things externally.  Only thorugh developing ourselves will be become more whole and until that time we are vulnerable to Projection.  Projection is also sometimes called Transference but both essentially mean that we seek to Substitute what is missing from external sources, especially when in close relationships with other people, eg mother and child, partners, therapist and patient, or teacher and student.

It does not only come in the form of filling our gaps but it can also be used to put things we don't want, onto others.  The happens especially with Blame, we might not want to accept certains things we have done or ways that we behave so we will blame someone else in an effort to eleviate ourselves of the burden that we are actually carrying and should own.

With some awareness and Discernment we should be able to see where this might be happening for us.  It might be the way we communicate with people, the way we say things to get a response from others and the way that we often feel very needy of others who can provide us with the things we don't like doing.  Remember, a giver can be as needy as the one receiving!