The heart being swayed will get in the way of the focus required to succeed
If one’s dreams are abstract and not concrete, one might as well not have a dream as one would do anything which leaves one at risk of doing something to cause oneself trouble.
If one’s dreams are the result of an action rather than an action in itself, one’s dreams are not pure and are better off not pursued as the impure can be easily taken advantage of at any time. This is because in order for there to be a balance, as there is in the universe, the consequence of wishing to receive rather than give, when put into action, will be loss.
If one’s dream is a concrete action one’s heart should not be swayed by it’s potential for success, the process of it succeeding or it having succeeded in any way as that would get in the way of such a dream’s success. This is because the heart being swayed will get in the way of the focus required to succeed.