A long time ago, it was customary for representatives of states to pay tribute to the Chinese emperor, who “ruled all under heaven.” The tributary system, as it was known, “acknowledged” China’s place at the center of everything. From a Chinese perspective, everything outside China was lower in the hierarchy.
For a number of reasons, including politics and geography, China lost steam around the time that Europe, led by Britain, embarked on the Industrial Revolution. Warlordism and colonialism ensured that for the next 200 years or so, China would stay behind while the West, and then Japan, modernized.