What do you wish you had known about caring for your dog before bringing it home?

Paul and I are talking about getting a dog. It may be a very long time before I'm ready or we may decide not to get a dog at all, but I'm at least open to considering it now. 

Before the twins were born, I would have laughed at the idea of us having a dog. But then along came Alistair and Emerick.

I've never seen little kids so obsessed with dogs. When they see a neighbor walking a dog across the street on the sidewalk, they ask to open the door so they can blow kisses. 50% of the tantrums the twins have ever had are over not getting to go hang out with a dog they've spotted.  

Emerick especially wants to pet every dog that walks near.  Yesterday, he took a book to bed with him about a therapy dog named Lola. This is usual behavior for him, schlepping a dog-related item around with him all day long and still clinging to it at night. When I checked on him, he had the book under his head as he was sleeping. And actually, it's not just dogs with him. Dogs are absolutely #1 for sure, but when he was at Paul's parents' house, he (a two year old who had never been around chickens before) was scooping up chickens and cradling them in his arms.  It astounds me the way kids are so strikingly their own person. 

Here's where you come in. I need your advice, input, and wisdom. I want to know what you wish you had known before buying your dog. <please>

Was it more expensive than you thought it would be?

Did your dog's demeanor end up different than what you knew that breed to be? 

Did you have trouble training the dog?

Did you learn something in the buying process? 

Did you end up doing all the work taking care of the dog?

I guess these questions are tilted pretty negative. If you had positive, unexpected things about your experience, that would be good for me to hear too.  

The three most daunting things about a dog for me: 1.) long term decision  2.) smell   3.) just more work.  And there's the costs too, which we've already looked at, and those are pretty sobering.  

That's me being real with you.   I would love to make my boys happy, but we can visit someone else's dogs or maybe have a lower maintenance animal if we decide dogs are too much (see #3).  

So, give it to me. Be honest -- please.  Good, bad, whatever.  Anything you think might help. 

You can post anonymously or message me as well if you want to be more discrete. ;)