For most people, once you smoke a lot of potent herb, whatever emotion you are already feeling will get magnified by ten times or more in intensity. ....So I have read.
I Arthur C. Clarke's novel Imperial Earth, an important part of the plot is the love one of the main characters has for a beautiful female. They had a whirlwind romance as young people, during which they made love while using an "emotion amplifier," although the details are only vaguely hinted at.
I've long believed that the "emotion amplifier" Clarke alluded to was marijuana.