Light at the end of the tunnel? The only tunnel that has a light at the end is that of the subway!
Ok, I'll sum up. The tunnels have two ends. You enter from one, you exit from the other. Unless the tunnel is not finished. In that case, you get in, but you have to go back to get out. Have in mind though that the tunnels we are referring to are a bit labyrinthine, so the light that can be seen is not always that of the exit. Also when we usually talk about life, we speak about doors. "Life
has two doors. I opened the first and went in, and until the sunset, I went out of the other!" (famous Greek song).