[I suppose I could have elaborated somewhat, but I'm just not feeling it]
The past has a tendency to oppress the future.
The weight of past efforts puts unwarranted value on their topics.
Incomplete activities can be seen as an investment and are given importance. This bias exists even though we have limited time, and we view our current/future actions against a return on investment (RoI).
It is a little true that there is some investment in the past. An overall understanding of the goals can be seen as an advantage compared with un-pursued new activities.
One's hobby needs to be the processing of past works; reviewing them for value and either identifying them as needing to be done or throwing them away. Otherwise the amount of ideas generated will become overwhelming.
Don't be chained to nostalgia or that tradition-of-self, filled with the regrets of things not completed "yet".