Persistence and hard work are close friends to Light. It becomes almost routine to fix this or that on L's clothing, adjusting something or the other until all is well. It's not terribly time-consuming, not on a day-to-day basis, and since Light's noticed that there are moments when L isn't missdressed, he can tell that his lessons, small and subtle as they may be, are working.

"You've taken to it. Teaching. I'm surprised. I didn't really think that would be something you enjoy so much, but I can tell that you do. I'm glad you'll find it useful."

In their world, they exist as foes. Neither knew of the other existence until the line was drawn and they found themselves on opposite sides. The past isn't forgotten because of a change in scenery, but they must adapt. Here, L is much more useful as a friend with no current benefit to having him as an opponent. They seem capable of challenging each other even when allies.

With a nod, Light finishes the sentence.

"Change so that we have time for dinner. I'm already dressed so I'll wait here."

It may not have been a big celebration, but Light guesses that L prefers small, intimate, and meaningful over a large party where most people won't even spend any significant amount of time with him.

And this is cheaper.