Pick the scenario and pack right. You have a weight and volume budget. Take the essentials, avoid dead weight.
Two days in the Estrela range, snow possible, -5 °C at night.
Summer, strong sun, you sleep out and refill water from streams.
Half a day on the trail, back to the car in the afternoon.
A summer afternoon by the river, a swim and some snacks.
A day along the shore, salt wind and sun with no shade.
A winter summit, ice and strong wind. Serious.
Plains at 38 °C, shade is rare, water is everything.
With kids, half a day, no rush and no hazards.
Two days by bike, everything has to fit in the panniers.
Run the trail light, only the bare essentials.
Several days, you sleep in refuges, no tent to carry.
A night watching the sky, far from the city lights.