Most areas host fairs, festivals, carnivals, or other fun events during the summer. Check your city's calendar online, or ask other people in the area whether they've heard of events. Check the websites or advertisements for nearby venues, including concert locations, theaters, and sports stadiums. Look at your town's or region's tourism website or brochures advertising events and find out what attracts people traveling from other locations. There might be anything from museums to merry go rounds lurking in your town, or in areas a short drive away. Spend a couple days with friends or family at a campsite, or camp in your backyard. Gather friends around a campfire or barbecue to tell scary stories and make s'mores. . Find a geocaching site online, and look up locations near you to see if anyone has hidden secret rewards. You can search for these caches or hide your own wither with a GPS unit or by finding the coordinates on a map. If weather, transportation, or a lack of events prevents you from leaving the house, take a fake vacation. Invite a couple friends for a sleepover and decorate your room like a palace, jungle, hotel, or anything you like. Go shopping for unusual foods and "souvenirs" to share with your guests. If the weather is rainy, dress up in swimsuits and sunglasses and lounge around indoors pretending you're visiting a location with a proper summer. If your current friends are out of town or busy, look through your old yearbooks, phone contacts, or emails and reconnect with people you used to know. Any of the activities above can be more fun with friends, or you can simply spend an afternoon catching up with each other or reminiscing. It could be anything, a house made out of cardboard or a simple 3D puzzle. This would help you think logically and help you to keep up your resilience.

TL;DR in Vietnamese:
Tham dự những sự kiện trong vùng. Vào vai một du khách để tìm hiểu thành phố bạn đang sống. Đi cắm trại. Chơi trò truy tìm kho báu. Tạo một kỳ nghỉ trong nhà. Liên lạc với bạn bè cũ. Thử lắp ráp một thứ gì đó.