Where did so many of us get the idea if we are too happy, something terrible is going to happen? We can't enjoy ourselves, can't let out guard down because we think that being hyper vigilant will protect us. It's magical thinking to believe that we can ward off disaster by not being too happy.
As the great philosopher Epictetus reminds us, "When considering the future, remember that all situations unfold as they do regardless of how we feel about them." We can exercise caution and care, we can plan and scheme, but to a great extent, life unfolds on a grander scale than all our scheming. Worry will do nothing to change the outcome.
It doesn't have to be hard. It's OK if it is easy.
Ryan, M.J. Instant Health and Happiness. Pg. 315.