Ejaculating feels good because Men are needed to want to breed. Women find nursing "pleasureable" because women need to want to keep babies fed and alive...
We're talking about caveman biology here...
As for the Sun...AFA..you should already know the answer to that. The sun sets early because the Great Overseer, Zolton, the ***** who created humanoid life on this planet 60,000 years ago, wants to reward us for our hard summer's labor in the fields...toiling away to grow the great sacrifice..by making it dark early so we won't **** and we'll instead travel to the clubs to dance and get laid by hawties until the next harvest cycle returns...