Left: an arrow 矢 (= An arrow ノ in the sky 天), right: a mouth 口 (here: a target)
The arrow hits the target, if it knows it.

At top: to know 知 (The arrow 矢 has a target 口, which it knows.), below: sun 日
Knowledge like a shining sun is true wisdom.

Outside: disease, illness 疒 (An ice 冫-cold building 广 makes sick.), inside: to know 知 (The arrow 矢 has a target 口, which it knows.)
The disease in respect to knowledge is to be: stupid.

Left: Insect 虫, right: to know 知 (The arrow 矢 has a target 口, which it knows.)
(In respect to building a web) The insect with (special) knowledge is: the spider.