This is a deep study SB....
We can surely say that the shepherd represents God.
Also, I think we need to remember that these gospels were written a long time after Jesus' ascension. This does not mean that they are wrong...but sometimes the writers did
compress information. Jesus might not have said exactly every word as we have it...or two events have been woven into one. This is why I've said to a member here that we cannot hang on to every word with our life. There has to be some lee-way and a basic understanding of God's nature and what He desires from us.
As to lost sheep...there are shepherds here even today.
I can tell you that he WILL leave the flock to go after one. This is because the lost sheep will most probably not find his way back but only go further and further (although anything is possible, of course).
The flock will tend to stay together...also there is a dog there that will keep the flock together. I wonder if
JohnDB knows if dogs were used back then?
Of course, it the task becomes too difficult or it takes too long, the shepherd will give up looking for the sheep. So are we to assume that God will stop looking for us? No. This is not what Jesus meant to say...He plainly said that the sheep was found...we should only read what is written.