"Second chances," Obi-Wan agrees with a small smile and a nod. "May we make the best of them."

In his case, it means sifting through his years of training and trying to relearn what it means to be both a Jedi and a mentor. He'll never not be a Jedi, despite there no longer being an order, but because there is no order, it means he has a chance to revisit what he's been taught. From what Ben has told him, Luke tried to rebuild, only to fall into the same traps as before.

He won't make those same mistakes again.