How does conditioner or fragrance in soap/shampoo stay in?

If soap or shampoo is truly effective in getting dirt off or out, then how can the conditioner in shampoo or fragrance in shampoo or soap not get washed off instantly as well?How does conditioner or fragrance in soap/shampoo stay in?
If the fragrance or conditioner molecules have a chemical affinity for hair, then that's how they ';stay in.'; Hair is a protein like silk or wool, made up of a sequence of amino acids. The amino acids have pendant groups like -COOH or -NH2, which form bonds with other molecules. You maybe right, however, that conditioner or fragrance molecules have little affinity for hair and may be washed out.