It ever was..

The matter has ceased to be a mystery to any one. Indeed, I wonder that it ever was a mystery.

How to say "it ever was a mystery" in the simplest and clearest way?

In this sentence : "I" think it used to be a mystery. Or "I" think it never was a mystery? ... Thank you.

The original sentence is perfectly clear. In the second instance, the second example, 'I think it never was a mystery', seems better to me.