the present moment is all we have
In nature, animals fight or chase one-another because someone is hungry. After the confrontation (or dinner) everyone goes their separate ways, carrying on with life instead of dwelling on what just happened for the next few hours or days. Nature flows simultaneously with time.
In the modern world, we encounter things like arguments, getting cut off in traffic, or Karen trying to ruin the cookout. Afterwards, we rarely go on with our lives, instead we relive the past situation and experiencing the same emotions allowing it to affect us long after the event happened. As humans we spend too much time stuck in the past.
The present moment is all we have. Everything that happened to you, every encounter, every decision and subsequent outcome made you who you are. This is not to say that we need to be happy about everything but we are the product of our experiences — good and bad. So live your life right now, and never look back because it’s all working out how it was meant to be.