knocking

Isn't it amazing how one action can trigger a memory that affects you so much. Sometimes good, sometimes bad but our minds are incredible machines that keep things locked up so well, stored away until they are needed, or until some trigger sets them off.
Today on the way home from the school run I saw someone knocking on a door, nothing strange about that, but they looked really desperate to get in, they were knocking the door, ringing the bell, banging on the glass, looking like they might lose it completely at any minute. I walked on, there was nothing I could do.
Then it hit me. The last time I was knocking on a door like that, the desperation I felt, I wanted to kick the door in, it was a porch and I'd have another door to face if I managed it. I had to get in, I needed to get in, the person inside needed me, I'd come to help them, I had to  help them, I had to get in.
 The person inside was already dead, I was about 4 hours too late.