Internal motivation
The human mind is programmed to be as lazy as possible. It is a very important trait because conserving energy is essential to ones survival (For a caveman). In such a prehistoric environment there are plenty of external motivators, usually because certain death follows one who idles .
Of recent times we have the luxury that we don’t die if we sit down and do nothing, we also have an environment where effort is directly correlated to reward. But we still have the tendency to rest whenever possible, even when we don’t really need to (The brain will exhaust itself long before the body).
So if someone has high aspirations for self actualisation and has to rely on their own self motivation they are forced with a conflicting mind-set. Part of them wants to conserve as much energy as possible, but another part of them wants to pump out as much work as possible. Unfortunately for most of us the lazy mindset usually wins.
In a work environment one is surrounded by managers who have the ability to threaten wages, that alone is a powerful source of motivation. For one to do a similar quantity of work in a self actualizing scenario one has to create their own motivation with similar moving power.
Some people recommend giving a friend a sum of money and telling them to donate it to charity it unless you meet a set goal. This is actually a really strong source of motivation, but it is maybe too much for overcoming mere laziness (If you had a goal to face a fear it would be more suitable).
A good one for laziness is simply to write a check list. If you have an realistic to-do list in front of you, being able to cross things off the list is often enough to get you to do them.
That is what I have been doing; creating a standard list of daily contributions to long-term goals is a great way to make sure one is travelling in the right direction.