TLIK – Absolutely true. Depending on your relationship with your child or student (and, of course, their age), there is a limited degree of influence you can have on their choice of friends, or on just about any choice that they will make.
The objective of Chinuch is not to force specific behaviors, but to implant a value system that will continue to guide your children and students when they are adults. Forcing compliance is generally counterproductive to this goal.