What does it mean to "look back" after putting our hand to the plow?

Luke 9:61-62 in context: The story begins as the Savior was traveling through a village, a certain man calls out and says that he would follow the Lord wherever He would go but then that man starts to retract his commitment of discipleship. Why?

I spent some time this morning studying , pondering what it means to "look back". I did some cross-referencing and searching foot-notes and found these descriptions to paraphrase:

Looking Back

1. Making excuses not to work. Choked by distractions or cares of mortality.
2. Wanting to serve on our own timeline. Don't like the inconvenience of service in the church.
3. Looking back longingly /or with jealousy. Thinking the grass is greener on the other side.
4. Fear of commitment. Probably ties in quite a bit to the first one mentioned.

-Come Follow Me - Study April, 1-14 (page 56)

In the cross-referencing I did, I also found a verse in D&C 67, "Again, verily I say unto you that it is your privilege, and a promise I give unto you that have been ordained unto this ministry, that inasmuch as you strip yourselves from jealousies and fears, and humble yourselves before me, for ye are not sufficiently humble, the veil shall be rent and you shall see me and know that I am - not with the carnal neither natural mind, but with the spiritual."

**I just thought it was interesting that jealousy and fear were vices so closely associated with each other and the roadblock to humility.... the humility so greatly needed in following the Lord wherever He goes.