Money, your keys, and time--all things you can lose, but not all things you can get back. Sure, the sting of losing a bet is far from pleasant, but eventually (and hopefully) that money will flow its way back to you. And when you lose your keys, you'll certainly find them again somewhere in your couch. If not, they're replaceable.

But time? Irretrievable. Absolutely. Lose time and you will not get it back.

Therefore, it's all the more critical that you protect your time, especially if you want to achieve all that you hope to accomplish. Here's how:

1. Schedule it very specifically

If you schedule your own time before anyone has their say and asks for some of it, you'll find yourself successfully protecting your time. Bill Gates himself follows this practice, although in a much more particular manner--his days are scheduled in five-minute increments, with every meeting timed.

2. Create a sacred space to be productive

Everyone works differently in different environments. Just as I need background noise to work effectively, others may need absolute library-silence to get things done. If you know what kind of environment is conducive for your success, invest effort into creating a space that will allow you to become the best worker you can be.

3. Get used to saying no

Say yes too easily to other people and you may be saying no to a life full of efficiency and success! When you decline certain requests, you, not others, are dictating how your time is used.

4. Be sure to say no effectively, but politely

Doris Clark in the Harvard Business Review says it best, "Managing your time is a constant balance--too loose, and you spin off in a million unproductive directions; too tight, and you eliminate serendipity and come off like a controlling prima donna." In other words, if you keep rejecting others when they ask for your time, you may needlessly alienate your network. To prevent this, don't ignore all of your requests, in the hopes of getting out of any possible future obligations. Instead, feel free to decline, but also suggest alternative options in order to preserve the relationship. For example, if someone wants to take you out to lunch to ask you for guidance or insight, you can request that they talk with you on the phone instead, as your busy schedule may not have room for a 1-2 hour long meeting.

You may not be able to get your time back, but protecting the time you do have will allow you to enjoy more free time than ever before. Perhaps you don't need to plan everything minute-by-minute like Bill Gates--then again, it wouldn't hurt to try.