This is a common occurrence for me since I don’t have much time to play. I often get about halfway through and then stop playing for months. When I come back to it I always want to start from the beginning and then the cycle happens again.
One example for me is Fallout 4
I’ve started Skyrim about 5 times but never really gotten anywhere in it.
I’ve re-started Resident Evil 5 from beginning about 10 times and just haven’t been able to drag my way all the way through. I’m about 2/3 of the way completed at this latest stage.