Hi Stéphane 
Injaw ,
What are you trying to do (I think I know, but be clear, please) and how are you trying to do it?
Yes, I owe some explanations. I had a simple image idea with street lamps in mind. Unfortunately, the technical aspect has dampened my enthusiasm. In 3D, everything is very complicated, from modeling (where I am most comfortable) to shading, lighting, rendering, etc. I'm going to take a break from all of this.
It is very complicated because there's so much disciplines involved. It's not just the technical, is the art part that is also very hard to grasp. In other words, you may know all about paying the guitar, all about music notes and reading music, but there's also the most important part, you actually have to play the guitar and make some cool tunes, and that part is not at all technical, it is artistic in it's nature. So all of that to say you have to not only learn Blender, but also focus on the what makes a good art piece appealing, otherwise you'll try to light your scene and it wont look good, no matter if you know how to model, you kinda have to know photography a bit since the same principles apply. So yeah, complicated, taking a break is good, but don't go about it for too long or procrastination will get the best of you and you'll never get back to it. Breaks are good and dangerous at the same time. See you in a week Stephane.
Injaw it is a good idea to take a break when things just don't work as you thought they would and it gets frustrating.
When you are ready, let us know what it is you are trying to do.
You may just need to adjust a setting on the lights, or you need to add more to the scene for light to bounce, you probably need to think more about the natural ambient light too.
did you do the cubicity course? In the beginning Kent explains how to adjust the lighting for the lantern. Of course it's not a course about lighting, perhaps another one will go further into details
