behind the curve
I don't understand what you mean by taking the shape of your skull.
Do you mean that they are starting to curve instead of being dead straight?
There's nothing bad about that. If they are thicker, this will happen more dramatically than it does to thin locks. Thin locks will straighten back out faster just due to their own weight. Fatter locks need to be a little longer for the weight to really pull enough to straighten them out.
I'm only speculating that this is what you meant.
Don't worry about it. You may be able to see how 1 or 2 of mine curve in some of my videos.