I totally agree with that. Some days you are not really in the right mind-set, or get frustratingly stuck on something, or there are too many distractions. Other days things are going well, progress is being made, and oops where did the day go ! Only work on it when you feel motivated otherwise it ceases to become a pleasure. You will get plenty of breaks whilst glue or paint is drying.
I have been three months on a boat, off and on, a bit most days. The one I am on now I have been going at almost two years. At least it helps avoid the endless Forensic Dramas on TV that the wife always has on.