Hooray for the "hoary-headed!" Sorry, a brief return to KJV language. This means the grey-haired man is the wise man. But before we equate wisdom to everyone with grey hair - and wicked motives to everyone who uses "Just for Men" to get grey out of their hair and beard - maybe we should examine everything in this proverb.
What is the second half of this verse referring to . . . an older person - or a crown of glory? It refers a little to both - but mostly to the crown of glory. There is only one other key passage where this admonition is given in connection with being older. It is found in 1 Peter 5:1-4 - and the admonition here refers to "elders" in the church. Oh, but there is much we can learn from it.
Therefore, I exhort the elders among you, as your fellow elder and witness of the sufferings of Christ, and a partaker also of the glory that is to be revealed, shepherd the flock of God among you, exercising oversight not under compulsion, but voluntarily, according to the will of God; and not for sordid gain, but with eagerness; nor yet as lording it over those allotted to your charge, but proving to be examples to the flock. And when the Chief Shepherd appears, you will receive the unfading crown of glory. 1 Peter 5:1-4
Note that this passage speaks of older me who do the following. First, they are active in the local church - serving at the highest levels of leadership - which means that they also exhibit the highest levels of servanthood to others.
Second, they voluntarily lead a life of giving and serving others - certainly a wise thing to do - and a godly thing to pursue. What do you VOLUNTEER for in working at the church? Where do you serve God and others there? Do they have to beg you to serve - or do you joyfully volunteer - even to clean toilets if that is necessary. This is wisdom on display!
Third, they serve according to God's will - not their own ego. Older men who learn to do this will be a blessing for hundreds of years in God's church - because younger men see powerful men who subdue their ego in preference to God's will. Too many churches have been destroyed because unwise men tried to serve God in the power of their own ego - thus serving the church became all about them and their desires for what THEY wanted the church to become. These men turn more into church "bosses" than churchmen who are servants of God's will first and foremost.
Fourth, they serve the church and others without thought of money. They are selfless men who do not desire salary and benefits - just blessing to God's people.
Fifth, This do this with eagerness - they LOVE serving God and His people. This goes back to serving God joyfully - even chomping at the bit to help in some way . . . or . . . being dragged griping and moaning because you have to sacrifice in some way your own wants to serve others - who honestly - ought to be serving you! Yeah, this way of living is the fool's way. A wise man knows a little serving in this life - means blessing in the next.
Sixth, older, wiser men serve God as examples to the rest of the flock. They don't lord it over those they lead - they lead in such a way that others follow - because they see the example of servanthood in their leaders.
So . . . this is most likely the way this old dude got his horey-headedness - or grey hair. He got it learning to serve God - not himself. He also knows that the one who does this will be rewarded by the "Chief Shepherd" - read Jesus - Who will give him the "crown of glory" when He comes. Not a bad way to be rewarded - but then again - not a bad way to live our lives either!