A longer day can change your brain before you even notice it.That burst of motivation people often feel in summer is not just a mood or a cultural habit. It has real roots in light, sleep, movement, social life, and biology. People may wake up with more energy, feel more willing to go outside, or find it easier to stay active. Of course, not everyone feels their best in summer, and heat can also drain energy. Still, for many people, the season b…