Many articles in the Watchtower would argue that living forever would not be boring by quoting how excited certain scientists were by studying one type of fish or insect for twenty years. The Watchtower would then say what if you had hundreds, thousands or millions of years to pursue your interests?
I always took that to mean humans would continue to produce new art, music and science. The natural state of humans is to grow. Stagnation equals death. That is the mistake most of my Witness friends made, they thought of life in the new system as not living as human beings but as museum exhibits.