On Motivation and Learning

Much of the scholarship on adult learning can be summarised in the following statement:
Adult's learn what they want to learn and what they find useful and applicable to their life experience.
In contrast, young people, certainly up to teenage years, are happy to learn what is put before them.  Adults, on the other hand, will discriminate and select when it comes to learning.
It stands to reason therefore that motivation for learning is an important topic in adult education.  Motivation theories address the question of why we learn as distinct from cognitive theories that try to explain how we learn.
When we use the term "motivation" in everyday life it can mean several different things - we often say "the football team came out motivated by the half-time talk" or such a person is a "motivational speaker".  In these examples we see motivation as a kind of energy or mind set that can be triggered for short intervals of time.  Another meaning we have for motivation suggests a long term quality, a propensity to achieve - one who is "motivated to get to the top".  But motivation is not always directed at achievement - when a crime is committed we know that every good detective looks for opportunity and motive in suspects. 
One drawback of everyday language is that we tend to think of motivation in the singular - we look for one reason for a particular action.  In reality, motivation is a complex matter; there is usually a mix of influences and mindset; circumstance and chance all play their part.
What then of motivation and learning?  I suggest that we need to consider two types of factors - those that predispose a person to take on a learning project and opportunity factors connected with the circumstances and conditions of learning.
Let's take a look at predisposition. If you ask adult returners, in a college for example, you will often hear people describe that they had been thinking about doing a course for a long time.  In my research (on adult's learning computer skills) I hear phrases such as: "I've always wanted to go back to school" or "I've been thinking about doing something about this for many years".  So it's clear that many people nurture a desire for learning.  What's interesting is that many people report that they were so inclined over a long period of time.  I think of this as a kind of priming.  It stands to reason that even when so 'primed' some people will act to learn and others will remain with an unfulfilled desire.
So, the other set of factors come into play - these are connected with the opportunity.  "I was in the supermarket and I seen the sign for the course and the two girls at the stand were very helpful"  this is how one of my informants describes a moment of opportunity.  At this point a person may (not necessarily as a conscious process) weigh up all the factors and ask questions such as:
What will I get from this?
How hard will it be?
How will other people regard my actions?
Will I have the time, space, money, support etc.?
This is the complex of motivation.  And here I am just describing one decision point.  Even when people start a course the questioning continues throughout.
As I said Adult's learn what they want to learn and what they find useful and applicable to their life experience.