Serendipity:
Serendipity is when you unexpectedly find something good or pleasant without actively searching for it.

Examples:
1. Receiving a dream job offer during a random chat at a party was a life-changing moment of serendipity.
2. It was pure serendipity that I found my old friend in a city so far from home.
3. It was pure serendipity when I found my lost earring while digging in the garden.