The Grass is always greener on the other side of the fence.
This is one of the few idioms that took me a long while to understand and contemplate upon; in hindsight it was probably due to my arrogance that I never bothered to look it up. In my younger years, I thought it meant that the other side was always better. Looking at my academic career, I started out with Royal Christian College; thinking I hit jackpot I was so elated only to find out that there were somethings I wasn’t too eager with the job. Maybe the more apt idiom ought to be
The other side of the prison cell looks better from my side of the cell