Actually, there have been a few challenges this week that have caused us a bit of stress and worry. Of course there have! Noone can maintain a permanently happy state because life throws curveballs.
What's important is how you handle the challenges (mentally and practically) and to keep perspective.
It's the end of the week, the sun is shining and I have time for a glass of wine in the garden before the kids come home. So, what's not to be happy about? Simple pleasures!