I really think that until you have a GSD, you have no idea. I know I didn't.
My GSD Rainer is about a year and a half old. I have a wife, and two young "human" boys ages 7 and 4. Before deciding on a GSD, we read lots of posts on here, talked to breeders, read breed specific articles and books and knew having a GSD would be a lot of work.
We were prepared to spend the money on whatever he would require, take him to obedience classes, and integrate him into our family. We didn't just decide to get a GSD, because they are so noble looking.. and yet, we were still not fully understanding.
Maybe it's not the case with all first time GSD owners, but despite our best efforts, there have been some really trying times.
Yes, despite our attempts to redirect to chewing toys, or other methods, our pup would still play bite our children and bring my wife to near tears, but we've worked through it.
Yes, though we've worked with him on relaxing when strangers, to him, are in the house, he has some issues with wanting to take matters into his own hands.
And even now, he's decided he doesn't much care for passing cars, and he wants to destroy certain ones, I've come up with a plan, with my trainer, to work on this issue.
There have definitely been times where I thought, though I love him, I wish we would have gotten a lap dog.. Life would have been so much easier. Now, it seems he's in his teenager phase, and testing his boundaries, which is a whole new level of enjoyment
We just can't picture our family without him, so.. we keep at it. We keep working with him. He's smart as all get out, We just have to learn how to communicate to him that certain behaviors are inappropriate. We have to help him grow to be the best dog he can be.
But yeah, in my opinion, you really don't know until you've experienced it yourself.