Falling of the wagon is fairly popular term among the Getting Things Done an practitioners and it mean situation when you stopped following the steps and let you system gone rust. Not sure if that’s not a sign on something deeper but that may be a different discussion.
To be fair we all fall of the wagon from time to time. There are better days and there are bad days and that’s ok. It’s unlikely we can constantly perform at 100% or 110%.
For the times when you are not feeling productive and things fell by the way side 99U blog has few tips on how to get back on the wagon.