theres much more to learn about nicotine, vaping, and e-liquids
All of these things can positively or negatively affect your smoking experience, and those things always change from session to session

According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2026 Report, COPD is defined by post-bronchodilator spirometry showing a fixed ratio of FEV1/FVC 50 mmHg) Altered mental status (hypercarbia) Signs of Lower Respiratory Infection (J44.0 trigger) Fever, productive purulent cough, consolidation on CXR or CT chest Positive sputum culture, elevated WBC/CRP/procalcitonin Clinical diagnosis of pneumonia (J12J18) or acute bronchitis (J20.x) documented by provider Systemic / Advanced Disease Features Barrel chest (emphysema: hyperinflation, increased AP diameter) Prolonged expiratory phase, diminished breath sounds Clubbing (suggests comorbid bronchiectasis or malignancy not typical COPD alone) Peripheral edema, elevated JVP (cor pulmonale / right heart failure) Cachexia, weight loss (systemic inflammation) Cyanosis central (severe hypoxemia), peripheral Symptoms alone (dyspnea, wheezing, cough) should NOT be coded when COPD is established as the confirmed diagnosis

The books message lies in its emphasis on taking control of ones thoughts and actions, rather than allowing external forces to dictate ones fate