There are lots of books on the theme of small things that bring happiness. What are yours, past, present or imagined? You can have more than three but I was thinking of Desmond's thread!
Here are some of mine:
1. planning a garden project then seeing it through to completion, over weeks or months
2. sitting outside when it's quiet with a cup of tea, watching clouds scud past
3. sliding into bed just after I've just changed the sheets - the scent and the feel of crisp clean cotton