The significance in thickness between the two is due to the different amount of pressure exerted on the walls of the heart. The left ventricle has a thicker wall because the blood must be pumped throughout the entire body (oxygenated blood), unlike the right ventricle, where blood is pumped simply to the lungs to be oxygenated (pulmonary system).
Because diet soda contains acid (pH) that would erode the teeth
I think check with someone. Being in over your head means that you feel like you've blown things out of proportion or you're speculating but aren't sure about something. Asking someone else for their opinion and advice is really helpful.