Wu Wang begins with a strong line correctly placed at the foot of the lower trigram Zhen, and Legge's translation shows its subject entirely free from insincerity, with good fortune attending any advance. Nothing is qualified. The hexagram's whole subject, action arising naturally rather than from calculation, is present in its purest form at the very first position, before circumstance has had any chance to complicate it.
Zhen is movement, and this is the one yang stroke generating that movement from below. The line does not describe a decision weighed and then taken; it describes an impulse that was never divided against itself in the first place. Classical commentary reads the good fortune as following from that undividedness rather than from any calculation of outcome, which is why the text can promise it without naming what the advance is toward.
Read against the rest of the figure, this position is the standard the others are tested against. The second harvests what it never planned for, the third suffers a loss it did not cause, the fifth falls ill without fault, and the sixth pushes the same innocent impulse one step too far. All of them show what happens to innocence once the world gets hold of it. Here, at the start, it is simply itself, and that alone is enough for the text to call the advance fortunate.