1. The ROI of a personal data‑science project is usually low
“the main conclusion is that it is not worth building your own solution, and investing this much time.” – brodo
“I spent a lot of time on this project, but it didn’t justify the hundreds of hours I invested.” – brodo
“I had a few months of data, but the insights were minimal.” – ej31
2. Tracking is only useful when it serves a concrete goal
“If I had that now with LLMs I could ask it ‘what year did xyz happen’.” – behehebd
“I track everything I eat, take body measurements, etc. because I have a goal.” – cj
“I only keep a simple daily journal with a photo a day.” – behehebd
3. The practice can become compulsive or anxiety‑driven
“The whole ‘quantified self’ movement might be more about OCD and perfectionism than anything else.” – flexagoon
“I had an obsession with logging every cup of water.” – aurmc
“It’s a mental health issue to track mood swings when you’re not clinically diagnosed.” – Noaidi
4. Privacy, ownership and the risk of data loss are major concerns
“I don’t want to give my data to third‑party services.” – antonyh
“If a company goes out of business, you lose your data.” – driverdan
“I want to keep my data locally and not let big tech own it.” – skyberrys
These four themes capture the bulk of the discussion: the cost‑benefit calculus, the need for a clear use case, the psychological toll of obsessive tracking, and the importance of data sovereignty.