Lies we tell ourselves: from healthy to life threatening

I don't remember who it was that said you need a crazy amount of optimism and courage to succeed. Sort of like a wing and a prayer. And maybe that's true.

In life, you are your own number one supporter. You should be the first to believe in yourself, because there will often be times when you will be the only person who's there to push you, to get things going. So that when you come on through the other side, you'll be able to look back and say 'I made it'.

Point is, it's healthy to believe in yourself and tell yourself you can do this.

Sadly, this isn't always the case. That healthy self-confidence often trespasses into something out of proportion, a delusion of what your life looks like and what you're capable of.
And when reality doesn't add up, our only option becomes the comforting lie.
We shut out anyone who tries to throw the truth at us. We scowl at them. We ignore them. We shout at them. We just don't like them.

My most recent example was just yesterday. This week, I'm at a theatre festival with my boyfriend, helping out if I can. And yesterday, after attending two plays - supposed comedies, that barely drew laughs, one of them with the hilarious punchline of a dead child - I couldn't help myself. I told my boyfriend that I think this festival is sloppy, badly-organized and to be honest, disappointing.
These accusations were not out of malice. They were based on facts. Facts such as the room was three quarters empty (50 out of 300, its full capacity), the plays were boring. By the end of the night, I had been bored by three shows and I've only been here two days.... As you see, not baseless issues in a comedy festival.
And his reactions when I told him this was "don't say that". The organizers are friends of ours, true, but I don't think that's a reason to lie. And he came up with all sorts of excuses. And I don't believe in excuses. You can find them for everything. Bottom line is, it doesn't work. If it was, you wouldn't need excuses.

One of the actors in one of the shows came up with another excuse....apparently, it was only their second time performing this show format and that's why it was boring. Well then, don't perform it if you know it's a flop.

To get back, you can't tell people the truth, because they don't want to hear it. And the more you counter their arguments by explaining they're senseless, the more upset they get.
And you see there's no point in telling them. So I wonder....when truth is so blatantly rejected, what do you do? Do you soldier on and keep telling them the truth? Or do you just keep it to yourself?

To me, keeping to yourself and just nodding along seems dishonest, but what do you think?