Disappearing Ink

I got a message

Pretend you'll guess what it said

Drive alone

Drive straight homeI did as instructed

Closed my door and locked it

Disappearing ink

but the words still stingI sat and wrote a letter

I described the weather

and the scene

Remembering...I forget tomorrow

For all the sickness and sorrow

Disappearing ink

but the words still stingWhat was I thinking?

What was I thinking?