The classic case is the frustrated worker, who can't yell at the boss but comes home and yells at the spouse, who yells at the children, who kick the dog, i.e. we take it out on the people we love. Suppose we were very envious of the relationship between our sister and our mother. Our feelings may never be expressed towards them directly but take the form of resentment and distrust of most other women. In the last example, instead of the hatred of one's sister and mother being turned on women in general, it could be turned against oneself. This is a commonly assumed dynamic in depression and suicide.
Love turns into hate or hate into love.
Hell has no fury like a spurned lover. Where there is intense friction between a child and a parent, it can be converted into exaggerated shows of affection, sometimes sickeningly sweet and overly polite. Or, the person who is unconsciously attracted to the same sex may develop an intense hatred of gays. Remember Freud's notion that the Oedipus and Electra Complexes are resolved by identification with the same sexed parent. In other cases, a person may associate with and emulate an admired person or group to reduce anxiety.