You meet someone and you're sure they're good peoples and normal until you make the mistake. You ask them for a favor or even worse, they offer to do something for you. Then it happens, or rather it doesn't happen. The date approaches and you try not ask about it as frantically as you feel. Then the day passes without the person coming through. They have flaked on you.
The feelings flash, anger, sadness, resentment. Personally, I'm not one to ask for favors or to ever depend on anyone else. I don't often accept even when someone offers their help, because I don't like to feel like I owe someone anything. In your new endeavor there will be people who will know because they are so close to you they know how often you use the restroom a day. Then there will be the people who you can't help but share your news with because it's so exciting. People, friends, family and even sometimes those you won't know will want to 'help'. They will offer sweetly and with enthusiasm. You won't want to impose, 'no but thank you' and then you'll shoot yourself in the foot and say yes.
They will, of course, have the best intentions. You'll believe them and stupidly you'll depend on them. There's the big things, like needing beta readers and then the not so big things that feel huge when they aren't done, like reviewing your book once it book has been posted.
Here's the thing, I'm sure they meant every word they said. The fact remains that more than half the people who promise you something won't come through. Whether it's being a beta reader, reading your book once it's been finished or writing a review of your book once they'd finished.
Know it, accept and breathe deep. Your loved ones, friends and acquaintances will flake on you. You will swear long and hard and then you'll wish harm on them and then finally you'll get over it. Flaking is going to happen, it will happen to you and at some point you will flake on someone.
My best advice is don't put all the eggs in one basket. I started with seven people who said they would be beta readers and I ended up with four and only two of them read all seven stories. If I had has many reviews as I'd been promised by family and friends, I'd be at over forty (I'm at 11 now). Accept that if you do accept assistance from others it won't always work out the way you hoped it would. That's life and just remember if it's really bad, there's something called karma.