Who is setting the boundaries for your life? What is currently determining your limitations, driving what you allow yourself to do? It’s hard to set boundaries with other people, but it’s hardest to set boundaries with yourself.

Life has a way of bringing up old lessons I thought I mastered. Lately, I’m in the process of re-learning this one: You must continually fight to maintain your line in the sand.

At every turn there’s a new temptation to relax your standards, to break your rules and routines. There’s a new rationale that the voice in your head is using, telling you why all of the boundaries you previously established are no longer valid.

Do you have a regularly established morning routine? Nothing like having kids, getting a pet, or even simply switching jobs to toss your morning schedule on its head. In one fell swoop, you have a whole new set of people to care for, expectations to live up to, or (so you believe) things to prove.

Do you have a strict cut-off time for when you put work away and go home to be with your family? Nothing like a promotion or a high-profile project to bring that voice in your head back: “That rule was fine in the past, but this project is critical, and you don’t want to disappoint your new manager!” This is especially potent when impostor syndrome rears its ugly head, and the fear of being revealed as a fake turns the pressure dial up to 10.

The truth is that there will always be something waiting to justify you relaxing a boundary. The only thing that suffers in the end, though, is you. Don’t believe the voice that tells you your priorities and goals don’t matter anymore. Ask yourself: Is this going to matter in 10 years? In that light, things like the stressful deadline for the current project you’re working on won’t seem so important.

You may need to adjust your boundaries. You might need to tweak your schedule. But you don’t need to give up what’s important to you.

And finally, don’t be afraid to set a boundary with others in order to protect the boundary you have set with yourself. There is no way around it: Either you set the rules which guide your life, or someone else sets them for you.