Left: side, direction 方, right: horizontal person , var. of correct 正. (When sleeping, one must occasionally turn to the other side to avoid pressure & bed sores & circulation problems.)
Mnemonic
The side of the lying person is fine/correct, but he must turn.
Is understood as a flat version of: 人 - Other radicals with 'person' are: sitting 匕, sitting cross-legged 夂, kneeling ⺈, skilled 才, bending マ,卩, slumped 㔾 or husband 夫
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