Will the Next Door Please Open Up?

You've probably heard the above cliche before...and you've probably had to remind yourself of it a few times. Did you know there's a second part to it? The full saying goes like this: 

When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.

I've unfortunately had a few instances in my life, as have many of us, where one painful door was slamming shut. Sometimes these doors were long overdue and it was actually a mixed blessing forcing me to revisit previous decisions. 

It's never easy and even if you know that it's for the best, and are thankful deep down...it's still hard. But then again, we're human and often afraid of the unknown.

Have you had to deal with a similar situation? What has helped you focus on the open door rather than on the closed one?