This is one of the major transits of mid-life, occurring in your very early forties, and for many people it coincides with a 'mid-life crisis.' Your youth is behind you and the second half of your life looms large. If you've been in a career or a relationship that was based more on other people's expectations than on what you wanted for yourself, now you'll question those choices and begin to move toward relationships, jobs and activities that are more expressive of who you are as an individual. This can be a difficult, even painful process; you'll have a lot to think about during this period.
One problem is that you feel more like acting instead of thinking -- you feel an incredible urge to break free from constraints, a mindset that isn't conducive to careful consideration. There's a strong sense of time slipping away, prompting a sense of urgency and propelling you to action. The most important factor to consider is whether or not a job, relationship or other situation gives you a inner sense of satisfaction. From here on out, all parts of your life need to be congruent with your own philosophy and attitudes, in order for you to feel that your life is meaningful.