It might be an understatement to say that time heals all wounds. We instinctively reduce stories of old to fantasy - a part of some other reality. Objectively this isn't true, it's just a fallacy of the human mind.
250 years ago people endured awful tragedy to deliver this holiday to the Americans reading this. People ran directly into gunfire, were impaled, starved and burned alive. People lived the rest of their lives without husbands and sons. It was an ugly business, but the people of the time valued their freedom so greatly that they died willingly.
In doing this they started a global movement. Before this revolution - roughly zero humans lived in a democracy. Today close to half of all humans live in a version of one.
Americans - imagine what it would take for you to opt in for that now, risking your life and your family. Enjoy your BBQ, laugh and be happy, but privately, in the back of your mind, marvel at what they did. And then think about the folks in other countries who are still fighting this battle.