What are life examples of unbelievers' futility of mind in Eph 4:17?

Paul's epistles should be understood spiritually. Thus, 'vanity of mind' is not natural futility but rather spiritual futility. So, to provide life examples is not to list useless things men do in their mortality, or man’s inept activities or knowledge in his natural state, but to perceive it in view of his eternal existence.

For an example of Paul's spiritual context, notice his attitude towards natural things and their futility, compared to the worth and significance of knowing Christ, here:

Php 3:7-11  But what things were gain to me, those I counted loss for Christ.  (8)  Yea doubtless, and I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them but dung, that I may win Christ,  (9)  And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:  (10)  That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;  (11)  If by any means I might attain unto the resurrection of the dead.

In summary, ‘vanity of mind’, and the loss one suffers, if one occupies one’s mind on temporary things, is in contrast to the value and excellency of the eternal things of Christ. To have a mind filled with goals, achievements, and knowledge of a temporary nature, is utter vanity, or futility, (or dung), in view of the knowledge of Christ and the pursuit of winning Christ and the eternal attributes and rewards that flow out of Him.