I was hooked after my first competition. Before that, we were just training together. Training together is fun, but at that stage for me it wasn't any different than teaching a trick, or an obedience task. It's when we stepped to the line, and completed a run that I realized I ADORED it. When Bentley and I stepped off the course at the end I started crying! We didn't even Q, haha.
And as for when to start, it 100% depends on the dog. With Bentley, we started as soon as we could. It was probably a mistake. If I remember correctly, he couldn't weave yet. We just wanted to get out there (hadn't really realized the importance of foundation skills at the time).
I think it's all about their mental ability. I want them out there if they have ALL of the obstacle skills & basic handling skills. That doesn't mean that they weave perfectly every time--in fact sometimes I think it's helpful if they're allowed to make mistakes in a trial environment. Though you can't technically train in the ring, there is something to "hey you popped out of the weaves you have to do it right to move on". Now again, that's not the attitude to take if you're trying to build drive or have a softer dog--so there again it depends on your dog. Some dogs realize they're making mistakes and worry or shut down. You want to make sure they're comfortable in the ring, and comfortable making mistakes and taking direction out there.
So for me, no, I wouldn't enter Novice on the condition of being ready for Open. I think there is something to be said for "on the job training". On the other hand, I wouldn't enter them if they weren't working on the skills, or perfecting the skills needed.
In other words, totally depends on the dog
