I've trained dogs most of my adult life and each dog teaches me something new. Ironically, the most 'complicated' dogs teach me the most.
Enter Blue Heeler:

Describing Ranger as "complicated" in an understatement. He is a fiercely devoted little dog who is convinced the world is trying to kill him. Clever, he is held back only by his own insecurities.
I am a lazy dog trainer. I like dogs who fetch because the fetch is the skeletal framework for almost everything else I teach. I don't like having to 'teach' a fetch. I want a natural fetcher. (Yeah, yeah, we can't always get what we want in life.) That said, Ranger taught me that a natural fetch isn't necessary to end up with a fanatical retriever.
As a puppy, Ranger was always underfoot as we ate supper. Naturally, he wanted some. Since he had absolutely no interest in retrieving a kong for the mere thrill of retrieving, I offered to "pay" him for bringing me the kong. He watched me toss the kong. Watched it land. Watched it roll. Rolled his eyes. Nada. Nothing.
Now here is the key. I didn't care. I didn't care one whit. At that point I didn't even LIKE Ranger, much less worry about whether or not he fetched. I had absolutely no aspirations of making Ranger into anything. He was a cow dog, nothing else, so I didn't burden Ranger with my expectations. His inability to fetch didn't let me down in any way. And guess what?
After a few nights of begging with no results, Ranger went over and picked up the kong. Surprised, I gave him an academy award and a bite of steak. Voila. Ranger had an epiphany. He didn't learn how to fetch. He learned how to exchange a kong for a piece of food. The concept of MONEY was born!
Again, because I didn't care, I didn't burden Ranger with any expectations. In very short time, he was a kong pest at meals and soon earned my interest. I would toss the kong, he would happily retrieve it for payment. Soon the bug bit him, and he no longer needed payment. Ranger had become a fanatical retriever of kongs and everything else thrown.
Hmmmmm . . . Mom had an epiphany.
The old school methods for teaching a reliable fetch are often brutal and over the years, I abandoned them. They simply didn't fit into my relationship with my dogs. My dogs are partners. I don't choke or ear pinch my partner. I taught a play retrieve and never had it bite me in the butt. (But I had natural retrievers!) Ranger taught me another way to get a retrieve with a dog who was not a natural retriever. It took a while, but the key was not putting unrealistic expectations on the dog or myself.
Enter Trace:

Trace is a Border Collie. He should retrieve. Wrong. We're making assumptions again. Trace has no natural retrieve. Trace has been bred to herd cattle, not retrieve dumbbells, flyballs, or anything else. Still, I like a dog to retrieve. Fortunately I had learned from my experience with Ranger. The world will not stop turning if Trace doesn't retrieve. In August, Trace will be two. Guess what Trace discovered this week?
Retrieving!
For some reason, a light bulb went off in his little head, and he discovered the joy of having a human throw a toy for him. In the past he had always enjoyed chasing the other dogs when they ran for a toy, but now Mr Trace has decided that a one-on-one game of fetch is an awesome way to pass the time.

And again, I learned something. Trace reinforced the idea that things don't have to be rushed. Everything happens in its own good time. When Trace was ready to retrieve, he would retrieve. I'm still taking my time with Trace. His herding skills aren't reliable. The raw talent is there. The control is not. I can bang it out of him, but I've been there, done that, got the t-shirt. Instead we'll let him grow up some more, get more obedience, get more maturity. In time, he'll be better than Lily. The talent is there. The important thing is not to get my ego wrapped up in a dog. If I play it wrong, I can ruin the dog, or get him killed by a cow.
I'm sure I could have forced the fetch issue with Trace and Ranger, but I would have had an awful time myself, and possibly ruined my relationship with my dogs. I think the biggest lesson I have learned over these years is DON'T LET YOUR EGO GET CAUGHT UP IN THE DOG. I have seen too many people stomp off the agility field, the obedience field, the tracking field, the schutzhund field, etc, because they let their sense of worth get caught up in a dog's performance.
You are not your dog. The sun will not fail to rise because your dog missed a contact zone in agility. The tide will not fail to come in because your dog blew an obedience pattern. And if the sheep scatter on the field, God won't love you any less.
This lesson took me years to learn. With each dog, I get less worked up over learning skills on a schedule. Other Half was doing some reading and proudly proclaimed that Dillon was "ahead of schedule" in his bird dog training. He is a clever boy, and it's tempting to start pushing him, but why? He'll be ready for dove season and duck season, but if he's not, so what? Training can be slow and fun for everyone, or we can push him and maybe make a star, or maybe we'll just take all the fun out of it for him and for us.

My first show dog taught me a most valuable lesson. Navarre was a star.

To this day, people may not remember me, but they remember him. They remember me as "Navarre's Mommy." He had more titles behind his name than I could count. He had so many awards that I couldn't keep them all. But most importantly, he was my partner, my Soul Dog. And I remember the first night I came home after he died. I distinctly recall that I would have given up every award, every title, everything that dog had won, if I could have had him greet me at the back gate just one more time.

And THAT is the gift Navarre gave to every dog I will ever own.