I believe "cleverness" refers to ingenuity; it's outside-the-box, and trades simplicity in one plane for sophistication in another.
However most "clever code" we come across is lopsided in this tradeoff, and might even require cleverness to understand, which it turns out is not very clever at all.
However most "clever code" we come across is lopsided in this tradeoff, and might even require cleverness to understand, which it turns out is not very clever at all.