Just when you think you're dealing with an equal, you may be brought up short.
Forgiveness is the name of the game, but don't be afraid to set some ground rules— such as no cellphones at the dinner table, or asking that they return a text from you that begins, URGNT.
Suddenly kids are balking at coming home during their vacations or are no longer available for lengthy phone chats.
While it's natural to miss the former intimacy, it helps to understand their increased need for distance is appropriate for this stage of their lives and not to take it as a personal affront.
If you're wondering about whether to say something, ask yourself if the behavior that's bothering you is serious, dangerous or simply unpleasant.
For instance: If your son appears unshaven and scruffy for the family reunion, well, that may not be pretty, but it's not life-threatening.
You may struggle with the want-to-fix-its, but if you jump in too quickly to unravel grown kids' dilemmas, their important problem-solving muscles won't have a chance to develop.
That said, there are still times during your kids' 20s when you do have to voice your concerns and get involved even if your kids don't want you to (and even if you aren't happy stepping in yourself).
After years of hands-on parenting, you may bristle at how often you must bite your tongue as your children make both smart and foolish decisions.
Parents still may be tempted to give unsolicited advice, do whatever's needed to protect kids from harm — and remind them to get car insurance.
And grown kids may be frustrating friends who don't return parents' calls, cancel dates at the last minute or text their buddies while dining with the family.
Plus, they're better able to see the other person's point of view.
Their frontal cortex is ripening like fine wine, and that means improved judgment, less impulsivity and a greater likelihood they'll think before they speak.