Why is this a Roller Coaster Ride?


I’m taking my wife to court so our custody arrangment can be flipped and I can be considered primary care giver due to her unstability. I have a very good attorney and she tells me I have an 80% shot of winning in court and on top of that the kids want to live with me and my wife. Why do I still feel like it’s a roller coaster ride? Shouldn’t I be happy with 80% odds? Is this just how it is? Is there anyone else out there that were told they had high odds of winning and didn’t? Just curious.