Observations:
1. There is an optimal level of testosterone level at which you enjoy CP the most let's denote it by t_max.
2. If your level is a lot below t_max then you will feel tired and sleepy and you will not be able to solve hard problems, most probably you sleep during thinking, i.e. body enters it natural cycle to restore testosterone.
3. If your testosterone levels are more than t_max, you will be thinking a lot but not about problems. You will not feel like solving problems.
Which means you need to get Light.