A job. 

Right after my son was born my wife and I were both on leave from work.  We had worked out where we would be working opposite schedules and one of us would always be home with the baby.  After he arrived, we both started thinking other ideas.  She wanted to stay home with him full time.  I thought it would be great if she could do that.  So, I started looking for a job that could pay more so she could quit her job.  We both felt strongly about it, so we gave notice at our current jobs and made the revision in our plans. 

Well, it took longer than I thought to lock in a new higher paying job, and at this point I'd already left my other one (they had found a replacement).  So, the bank account was the only pay check as we waited on a particular job that just seemed like the right one.  And, of course, it came through in time and with the right offer and all that.  -click-

Maybe things clicking is usually not so labor intensive, but this is the one I think of when I think about how it just clicked.  It worked out.  Just how we needed it to.  I have always been very grateful for that.