When someone's strength reached Zhou Tian's level, few things could stimulate him. However, noticing that the secret activities he was engaged in could provide that excitement, Zhou Tian developed more interest in carrying them out.
Zhou Tian didn't know the true mentality of a monster, but he was a human dressed in a monster's skin. Humans, generally, are quite fond of excitement.
Being fond of excitement, many would engage in activities like bungee jumping or riding roller coasters, and some would even participate in high-stakes gambling or dangerous activities.
Most people acknowledge the danger of their actions but yearn for the thrill, the feeling of their heart racing. Despite being well aware of the risks, many still undertake such activities due to human nature.
While Zhou Tian was not particularly fond of excitement, human nature is such that after a long time without stimulation, encountering an exciting event would definitely pique his curiosity for quite some time.