Why youngsters do not like to hear advises. They feel it is their choice to live, explore and understand life. There is no place for others to dominate their thoughts. They will listen to their friend's advise, which may be more dearly to them than any elder giving lecture for hours. The maturity as on that date doesn’t allow them to listen to anyone except their friends. Even that friendship may be short lived.
Sometimes through mistakes one may learn things, bigger mistakes bigger learning. Till mistakes are domestic and doesn’t invite family reputation or legal interference every thing is interesting, once it crosses a limit accidentally or wantonly the damages would be dreadful.
Youth is the age when one sensibly hears and sees most of the things fresh and builds hopes for future and dreams thinking that these things are going to be interesting to them throughout their lives. Only when they cross the youth age they will realise that what they crossed are routine and they are only passers bye. The understanding and crossing of this phase is maturity. For a few this phase may not come for many years, with the result they loose the capacity to coexist with their peers socially, economically, professionally.
Do not advise. Let youth understand life themselves. Elders role is to guide and not to follow. Youngsters role is to analyse and decide whether to follow elders, well wishes and friends guidance. only then individuality will develop. This would lead to confidence followed by success. Since parents are matured enough to appreciate this fact please don’t advise. It will only spoil their ability to innovate and explore and be an example to be a mentor.