"Adamfell that men might be; and men are, that they might have joy." Lehi taught, "And now, behold, if Adam had not transgressed he would not have fallen, but he would have remained in the garden of Eden... and they must have remained forever, and had no end. And they would have had no children; wherefore they would have remained in a state of innocence, having no joy, for they knew no misery; doing no good, for they knew no sin." (2 Nephi 2)
When I was a little boy I chose to take a stick and knock off the tops of my next-door neighbor's flowers. Bad choice. I had to suffer the consequence. I was required to pay her for the damaged plants with my very own money. I learned at a young age that I was accountable for my actions.
We all have choices. We do not, however, get to choose the consequence for those choices. With a certain choice comes a certain consequence. If we want to be happy we need to choose to follow Jesus Christ. It's as simple as that.