今日有感而发，整整5年太不容易了。What is "machine learning," and what are things like "logistic regression," "decision trees," "random forests," "support vector machines," etc.?How are these things related to artificial intelligence? To understand these concepts, I spent nearly 5 years, approximately over 1800 days, delving into the foundational mathematical theories. Especially at the crucial moment towards the end of 2023, I started learning "R language," and suddenly everything became clear. Finally, after a whole five years, every day spent pondering what they are and how to use them, the arduous journey of deep learning came to an end. It was a challenging period of self-improvement, with no one to share, no one to support, and no one to understand. However, on January 11, 2024, today, I completed this path and finally embarked on a new journey: implementing an AI stock trading model. Note: Many thanks Dr. Adrian Banner, Dr. David C. Lay, Dr. Steven R. Lay, Dr. Judi J. McDonald, and Professor Robert Kabacoff