Well, one of my happiest memory from childhood was from when one of my cats went missing. She was the mother of the other three and, so far, the only calm and patient cat I've ever had. She was missing for over one week, but one monday morning I woke to the sight of her, all dirty and skinny, by my foot on the bed. I actually cried; cats usually show up dead or never at all.
My most recent happiest moment was from an exam I took to become a millitary officer

here in São Paulo, Brazil. It is a difficult exam that requires both academic and athletic skills, and they only call around 200 people; 90 spots the year I applied (15 for women). When over 3,000 apply for the test, it's really The competition.
So, it was happy because my father, to whom I don't have a good relationship with - it's bad at best! -, took me every day for my physical exams, and kept on checking the internet and calling friends to get news on results (he's an officer himself and took the exam years ago). He even gave me tips for the jump test, and was worried about my swimming.
It was really nice to see him worried about my progress

(I went well on everything, except I didn't pass the psychological exam. Think of that what you want

)