This is used when the third time one tries something, one achieves a successful outcome.
On Saturday July 2, I commuted to work on my bike. As you may recall the 1st time it rained heavily about 3 miles from work. I was soaked but, luckily my place has a laundry facility so I was able to dry out. My second commute resulted in heavy down poor with hail and lightening just as I left work. Lucky to be alive. My latest and 3rd commute resulted in a beautiful relaxing ride to and from work.