1.  Large men with small dogs

2. Old couples walking together holding hands

3. When a super cute baby makes eye contact with you and smiles

4. Catching a glimpse of a rainbow

5. Singing in the shower

6. And then there's always this:

7. And this!

8. Watching people greet their loved ones at the arrivals terminal

9. When a stranger helps you with the door or something you're dropped.