There is a hundred thousands of things happening all day. Small things or big things. The sun shines, you got married, the ice cream is great, someone rejected you, someone said thank you to you, another one didn't.
You decide how you react and what you take out of it (could also simply be nothing).
Just be aware and what things do to you. Be curious and in a constant mindset of learning and observation.
If you are stuck in your own thoughts and take everything that it happens to you, you will always be reactive. If you flip it around, have an intention and you observe how things happen with a clear mind, you will be in more control and not so dependant on what happens. And even the things that happen, you will understand them better and will get smarter about how to handle them the next time.