Set & Setting
The same amount can be a good evening or a bad one depending on your head and your surroundings.
"Set and setting" is an old harm-reduction idea, and it holds up: the effect of a drug isn't just about the dose. Your mindset going in (set) and your physical and social environment (setting) shape the experience enormously, and unlike potency, they're things you can actually choose. With cannabis, which so often turns a mood up rather than replacing it, they matter more than people realise.
Set: the head you bring to it
Cannabis tends to amplify wherever you already are rather than override it. Go in anxious, stressed, paranoid or low, and it can dial those feelings up instead of smoothing them out: a racing, looping, "everyone can tell" kind of high that's the opposite of relaxing. Go in relaxed and it's far more likely to be pleasant. The practical read: if you're in a bad headspace, that's the worst time to use, not the best. Using to escape a genuinely rough mood is also the pattern most likely to tip into problem use over time (that's the ground covered in Using to Cope).
Setting: where and who with
Familiar, comfortable, safe surroundings make a good experience far more likely, while unfamiliar, chaotic or high-pressure ones do the reverse. Being somewhere you feel secure, with people you trust, takes a lot of the anxious edge off. Being out of your depth, around people you don't know well, or somewhere you can't easily leave, stacks the odds toward a bad time. If you're trying something stronger or a new route, doing it somewhere safe with someone sober-ish around is simple, sensible harm reduction.
A few practical anchors
Small things genuinely help tilt the odds. Have water and a snack to hand. Being dehydrated or hungry makes everything feel worse, and low blood sugar can mimic the shaky, unwell part of being too high. Don't use somewhere you'll have to suddenly perform or deal with strangers if that's likely to make you anxious. And if a particular place, crowd or situation reliably gives you a bad or paranoid high, that's real data. Believe it, and change the setting rather than pushing through it.