One of the pious slaves of Allah once advised :
if you see someone older than you, say to yourself, "this is somebody who was born before me, so he has aqcuired more good deeds than me, so he is better than me".
And if you see someone younger than you, say, "this is somebody who has not yet sinned as much as me, so he is better than me".
This is how a Muslim should be. By this advise we can seek to further implement the hadeeth, "he who does not respect our elders or show mercy to our youngsters is not a complete pious believer."