Why are we told to avoid pleasurable things? (mostly)

One of the many questions posed by Shelby as end of the year thought provokers caught my eye and I figured I would respond to it.

Shelby asks why we are told to avoid pleasurable things, but I ask where and when were you or anybody told this?

I have been taught from the youngest age to seek out things that make me happy, things that give me pleasure, things that give me pain of some sort, I was told to avoid.
I feel that there are many human being that follow this theory of life. In fact the theory is even bolstered by Freud's publicized theory.

The pleasure principle is a psychoanalytic concept, originated by Sigmund Freud. The pleasure principle states that people seek pleasure and avoid pain, i.e., people seek to satisfy biological and psychological needs.An individual's id follows the pleasure principle and rules early life, but, as one matures, one learns the need to endure pain and defer gratification, because of the exigencies and obstacles of reality. In Freud's words, “an ego thus educated has become reasonable; it no longer lets itself be governed by the pleasure principle, but obeys the reality principle, which also at bottom seeks to obtain pleasure, but pleasure which is assured through taking account of reality, even though it is pleasure postponed and diminished”.

My question is: Where are there examples of people being taught to avoid pleasurable things or activities?

The Gestalt Effect

The Gestalt effect refers to the form-forming capability of our senses, particularly with respect to the visual recognition of figures and whole forms instead of just a collection of simple lines and curves. In psychology, gestaltism is often opposed to structuralism and Wundt. The phrase "The whole is greater than the sum of the parts" is often used when explaining Gestalt theory.

The investigations developed at the beginning of the 20th century, based on traditional scientific methodology, divided the object of study into a set of elements that could be analyzed separately with the objective of reducing the complexity of this object. Contrary to this methodology, the school of Gestalt practiced a series of theoretical and methodological principles that attempted to redefine the approach to psychological research.
The theoretical principles are the following:
--Principle of Totality - The conscious experience must be considered globally (by taking into account all the physical and mental aspects of the individual simultaneously) because the nature of the mind demands that each component be considered as part of a system of dynamic relationships.
--Principle of psychophysical isomorphism - A correlation exists between conscious experience and cerebral activity.
Based on the principles above the following methodological principles are defined:
--Phenomenon Experimental Analysis - In relation to the Totality Principle any psychological research should take as a starting point phenomena and not be solely focused on sensory qualities.
--Biotic Experiment - The School of Gestalt established a need to conduct real experiments which sharply contrasted with and opposed classic laboratory experiments. This signified experimenting in natural situations, developed in real conditions, in which it would be possible to reproduce, with higher fidelity, what would be habitual for a subject.

I read a separate article on the Gestalt Effect in relation to seeing faces in the clouds or in an irregular grain of wood, etc. and I do not fully understand the effect yet, and I'm not exactly sure where this post is going, but I am fairly certain of the relativity it possesses in correlation to the course material so I'm curious how R.C. and Gestalt react with one another.