Liu Yong's Klang Ganzhou was praised by Su Dongpo as "not reducing the height of the Tang people". The "height of Tang people" here not only refers to the literary achievements of Tang poetry, but also covers the poet's description of the scenery. For example, Du Fu's description of climbing consciousness.
Therefore, the meaning of "I don't understand the heights of Tang people" is simply that I have failed to fully understand and comprehend the wonderful artistic achievements in Tang poetry, which is embodied in my poor understanding and appreciation of Liu Yong's works such as Basheng Ganzhou.