A decent chunk of parenting, especially for those with older kids, is taking stock of the life decisions that they make with little parental influence. It is living proof of how their upbringing has influenced the path that they go down, and/or a reflection of their personality that no amount of conscientious parenting was ever going to change, depending on how a parent looks at it. Also, most young people are pretty dumb in a lot of ways, no matter what. It is something that moms and dads have to be somewhat sympathetic to.
The thing to be conscious of is that kids are still learning. Of course, there will come a time when they have to grow up, and that doesn't mean that they are totally free from responsibility or consequences. However, it is important to give them some grace and not be the kind of parent who they are afraid to share their failures with. In the grand scheme of things, most parents would prefer an imperfect child who keeps in regular contact with them to a successful one who cuts them off because of their past behavior.