exert oneself, restless, unaware of one's feelings
忞 centers on a state of inner turmoil and effort: exerting oneself restlessly while being disconnected from one's own feelings. The meanings describe a person who is agitated and striving but lacks self-awareness.
忞 combines 文 (pattern, writing) with 心 (heart, mind). The exact historical development is uncertain, but it likely expresses a patterned or agitated state of mind.
The top 文 suggests a tangled pattern, and the bottom 心 is the heart. Imagine your heart tangled in a restless pattern, making you exert yourself without understanding your own feelings.
For ビン, picture a bin full of tangled thoughts: bin -> ビン, and your heart is restless like the jumbled contents of the bin.