More than a year ago, I decided to spend more time writing to share some of the ideas I’ve developed over the years. Imagining how I could do it and setting my plans in place was fun. So much fun I forgot the most basic rule of planning: It’s not what you plan to do that comes first, it’s what you’re willing to give up to make time and space to do it.

As I plunged ahead in the excitement, I realized little of it would ever happen. The reason was simple: I had no time or energy available. As the head of a business, most of my time was spoken for. I had people who depended on me, clients who expected service, and I needed to pay attention to everything from marketing to finances and computer services.

What I did to solve my difficulty was retire. I gave up my job to pursue my dream. I’m not suggesting this is the only way, or the right way. For most people, it won’t even be an option. I only mention it to show that moving forward always means leaving something behind; often something you don’t much want to let go.

I frequently meet people who tell me they are on the edge of some great endeavor. Yet they never get started, because they’re waiting: waiting to finish something they’re involved in; waiting to feel sufficiently secure to take the risk; waiting until their children are grown, or their spouse doesn’t need to travel so much; waiting for enough savings to hold onto; waiting for the right time.

There isn’t a right time. There’s now, there’s sometime, and there’s never. Any time you start to think about starting, there will inevitably be something in your way: something important you don’t want to give up . It’s human to want to have it all: the exciting job; being a terrific parent; becoming a leading light in the community; and writing the Great American/Australian/British/Canadian Novel at the same time. Get a grip, my friend. It’s not possible. Choices will make always require you to leave other options behind, probably for ever.

A good part of the skill of living is the willingness to let things go without regret. Choose what seems best, acknowledge what you may have to give up to obtain it, and get on with your life. Don’t look back. Not now, not ever. Banish thoughts about what might have been. It wasn’t. Besides, whatevr you imagine would have happened is virtually certain to be wrong. People usually believe the roads they didn’t take would have been better than the ones they did. It’s just as likely those roads would have been far worse; or more or less the same.

Above all, don’t join in the national pastime of synchronized whining about the difficulties preventing you from doing what you really want. Either get on with it, if you truly want to, paying the price it demands and enjoying whatever you achieve; or shut up and accept you aren’t willing to pay, so you can’t have the goods. You cannot have it all. Get used to it.

Adrian Savage is an English author and retired business executive who lives in Tucson, Arizona. You can read his thoughts most days at Slow Leadership, the site for anyone who wants to bring back the taste, zest and satisfaction to leadership; and at The Coyote Within.