Everyone has that feeling, but i ve seen few people who are always happy. They had all luck to when it comes to job, career, partner. They are always in success mode. No look backs. Wish i was one of them :)

That's not exactly why, but I think I have a bit of an aversion to happiness.

After the high comes the low

Not scared of it. But I remind myself that there are always lows are highs

[media=https://www.youtube.com/watch?v=akvj7IraD3s]

That’s actually one of the beliefs/superstitions in my culture. If you were laughing hard you wish/pray that it’s a good laugh not followed by sorrows

I'd rather be content then happy. Its harder to find but longer lasting when you do.

Not scared, nope .....:)

I think you wanted to type have not how. My answer is also same as yours.