I often hear this phrase. It sounds like it has an obvious meaning. However I find it most often represents a lack of courage or the right kind of courage to act on some conviction. What's missing behind that comment is emotional intensity to overcome habitual procrastination to what is best, not simply rational. I mean by rational the easy way that seems to make sense even though there is a better way. Honesty is not always accuracy. Pour out your heart where someone can encourage you with the right kind of courage that I call inspiration.
No longer relying on "just being honest" removes the need to say "I was only joking", when you weren't, after seeing how you hurt someone or yourself by what was said. What is the answer then? Pour out your heart and listen as you do. What you hear will become strength and loving rather than weak and brutally honest. Psalm 62:8,11-12