Everyone always has something, they’re stressed about or perhaps even something to be upset/angry about. If you sit/lay/walk whilst focusing only on your breath, everything will automatically fade away for a few moments, and you’re not thinking about, what may happen in 5 minutes or further. It’s just you being spiritual present with yourself
By remembering that meditation is so much more pleasurable when one isn’t stressed. It’s possible to not just calm down but to experience real joy.