We have only one reserve or source from which we can take energy for the further development — this is sexual energy.
Someone can control the manifestations of their sexuality, while others can not. The level of self-awareness of our sex partner is very important, it depends a lot of it.
Sexuality is both a gross, physical level, and a subtle mental. And if the causal subtlest level is also connected, then there is already a chance to begin to experience pleasure not at the level of animals like ordinary people, but at those levels at which a human is supposed to.