Ask for forgiveness, not permission.
People around us—parents, bosses, partners—tend to deny things on an emotional basis, but if you just do the things that are important to you, these people will be much more likely to accept them.
Try it, and then justify it.
Don’t ask for permission if it’s not going to devastate those around you, if the damage you might cause is moderate or reversible.
Get good at being a troublemaker.
And say sorry when you really screw up.