In the past seven years, my weight has increased by 15 kilograms, mainly during my college years and the first year of work. I have made several attempts to lose weight, but all have ended in failure. The longest record was two weeks of continuous running, four to five kilometers per day, but my knees almost gave out. Afterwards, climbing stairs would cause knee pain, and it took some time to recover. But since then, whenever I engage in intense exercise for too long, the area below my knees would hurt. Wearing knee pads helps a lot.
Not to brag, but I'm quite good at sports. As long as it's a sport I'm interested in, I can usually play it decently (compared to the people around me), including soccer, table tennis, badminton, billiards, running (medium to long distance, not so good at sprinting), and even basketball. However, I almost always encounter someone better than me in any sport, some significantly better and some just slightly better. Except for billiards, I haven't encountered anyone my age who is better than me. One reason is that billiards is not a very popular sport, and I don't have anyone around me who specifically practices it. Another reason is that my hometown used to have a billiards hall (with only a few billiard tables), and I started playing when I was just tall enough to reach the table. My billiards skills were mainly developed in elementary school, so you could say it's like a foundation. After leaving my hometown for middle school, I played billiards very rarely, and only picked it up again in college.
One characteristic of sports is that those who have undergone long-term training are significantly better than casual enthusiasts (excluding those with exceptional talent). For example, because of my quick reflexes and good endurance, I play badminton quite well among enthusiasts. But the first time I encountered someone who had been practicing for a few years, I was beaten 3:21, completely outplayed. This person didn't even go easy on me (maybe they did, but I didn't notice).
Always encountering people better than me also highlights one of my problems: I tend to only scratch the surface of things and lack perseverance. I haven't put in sustained effort for many years in any particular project.
Recently, I have started another attempt to lose weight, focusing on jump rope and bodyweight training, with occasional running.