We used to joke that Robbie had threshold issues. He was great with people (except the postal carrier) outside the house and in the house but not at the door. Even with friends he would go a little nutty barking his head off if someone stood in the doorway.
Now I have threshold issues. When I come home I pause at the door to listen for him on the other side. When I leave I turn to tell him how long I'll be. It makes comings and goings particularly difficult.
A few years ago on retreat the director talked about the parable of the prodigal son and focussed on how the father, seeing his son a long way off, runs out to greet him with an embrace and a kiss. He asked us if we knew that God, seeing us a long way off runs out to greet us. I thought of Robbie always thrilled to see me whether I had been gone a half hour or a day. After that he was always a special reminder to me of God's love.