Honesty is important—that should go without saying.
What I'm talking about is not the general sense of honesty where you tell your friends and loved ones eighty-percent-truths mixed in with what they want to hear, but withholding things that might hurt their feelings. Truths like they don’t know how to sing; or their idea for a screenplay is terrible; or that their experimental cooking is inedible - bordering on human cruelty. That kind of honesty is, well, kind, but it doesn’t help them grow as an individual.
Real honesty is telling someone what you really feel. Even if the truth could hurt them or you or your relationship. Opening them and yourself up to a truth that could hurt at the time, but down the road can be looked back upon as a pivotal point. It could be something as menial as their cooking sucks, or as major as your relationship isn't working.
Real honesty is also telling yourself the truth, even if you’ve been repressing it for so long. Accepting that you’ve been in denial about a situation. All the while forcing yourself to see the silver lining when deep, deep down you knew the truth and didn’t want to accept it. The silver lining is a coping mechanism, but it also stops growth. It prevents you from facing facts, addressing your failings and moving forward.
I’m not saying that one should be brutally honest with people all the time. But we shouldn’t shy away from it either.
If you’re in a shitty relationship - talk about it. It will either save the relationship or save both parties from a bad relationship.
If you don’t like your job - talk to your boss. Either he’ll hear your concerns and address them with you, or he’ll ignore them, and you’ll know it’s time to look elsewhere.
If you’ve been telling yourself an awkward truth for a long time - something that deep down you know isn’t 100% right - examine it. Talk through it with a friend or a therapist. Being honest with yourself is the first step to realising that there are things we can control, and things that we can’t. The sooner that you understand that, the sooner you can move forward with less stress and in a direction you choose.
The flip side of this is if you hear an awkward truth, one you didn't want to hear or didn't see coming, embrace it. Be grateful for it. The odds are you knew deep down what was said to you was true and you simply weren't ready to hear it. Or worse, you were lying to yourself. It may not be easy to understand at the time, but given a little time, you'll be thankful for that person's honesty.