We got a card from a regular customer at work today. She's just retired from teaching and said 'It makes all the difference when people are polite, friendly and kind.'
It's a shame... I can't think of anything else that made me particularly happy today.
Edit: actually, I've thought of something. I've had a little weed in the cupboard all week - just a couple of joint's worth. The thing that's made me happy is that it's still in the cupboard - I told myself on Monday I'd only have it when I was out walking, and I've stuck to that. It's not like I've not had the opportunity or inclination either. So this is a Good Thing, and definitely worthy of recognition.