Here is someone looking back at a lost relationship and trying to measure how far they have come. The speaker begins by saying that writing has proved they can heal, then lists what they still miss: a voice in the morning, endless arguments, a kiss on the forehead before sleep. These are small, ordinary details, and they make the loss feel real. The speaker also admits that those kisses once hurt to remember, because the thought of them going to someone else was unbearable.
The turn comes with "But now": the speaker no longer misses the person "in that way." That phrase matters, since it suggests some feeling remains, just not the painful longing. The speaker imagines a future meeting, a smile and a wave, and everything being okay. The last line, "But not tonight," undercuts that calm. The mood is quiet, honest, and tender, and it shows healing as something uneven, not finished.