I work with progressions in my consultations. They're a crucial part of any chart analysis that involves past, present or future changes. Transits will tell you part of the story, but it's incomplete without an analysis of progressions.
Your natal planets are moved (progressed) through the signs, a certain number of degrees per month or year. The Progressed Moon is the fastest moving planet, taking a tour of each sign for (roughly) two and a half years. Most people will get a chance to experience all the signs (via their Progressed Moon) at least twice in their lives.
The Progressed Moon is your evolving needs. You don't have the same needs now, as you did when you were five (hopefully). And you can feel it when your Progressed Moon changes signs. You'll feel the shift from passive/confused/sensitive to active/aggressive/impatient when your Moon moves from Pisces to Aries. And then from restless to more settled (or at least, more content) when your Moon moves from Aries to Taurus.
But this impacts more than your moods. The Progressed Moon can trigger marriage, divorce, career changes, etc. You may attract people with the same Sun sign as your Progressed Moon sign (pay attention when this happens...they're in your life to help you work with that energy). If your partner suddenly changes their tune (they want to end things, or they want to deepen the commitment) it's possible that their Progressed Moon has moved to the next sign.
People handle these shifts differently. I've seen the Progressed Moon in Taurus stabilize a relationship, but I've also seen it mire someone in an obsession that they didn't break out of until their Moon progressed into Gemini. Some signs support certain efforts more than others. Progressed Moon is Aries is the classic time to start something that demands initiative and ambition (a new business/job). Progressed Moon in Capricorn is great if you need to focus/get serious/grow up. This doesn't mean that you should put off doing something until your Moon moves into a particular sign. You're ready when you're ready. But pay attention to how you're feeling (calm, withdrawn, adventurous) and make allowances.
Of course, you also need to factor in the house your Progressed Moon is moving through, and the aspects it makes to your natal planets.
If you want more insight into why you're feeling what you're feeling, check out your Progressed Moon. www.astro.com has a chart option that shows all your progressed planets.