Sometimes, people have life problems that can be entirely solved by doing one thing. (doing X made my life 0.1% better, PERMANENTLY!) These are not things like "This TAP made me exercise more frequently", but rather like "moving my scale into my doorway made me weigh myself more, causing me to exercise more frequently" - a one-shot solution that makes a reasonable amount of progress in solving a problem.
I've found that I've had a couple of life problems that I couldn't solve because I didn't know what the solution was, not because it was hard to solve - once I thought of the solution, implementation was not that difficult. I'm looking to collect various one-shot solutions to problems to expand my solution space, as well as potentially find solutions to problems that I didn't realize I had.
Please only put one problem-solution pair per answer.
Reading https://www.amazon.com/Allen-Carrs-Easy-Stop-Smoking-ebook/dp/B0051XSN50/ enabled me to stop smoking very easily, and I've not wanted a smoke in 25+ years now.
Yes, I think it was where he explained that you don't really feel better when you smoke. What happens is that a smoker feels worse in the times they don't smoke, and then a cigarette brings them up to normal again for a short while; so while you're smoking you feel as good as a non-smoker feels all the time. But I don't know if just reading that would have done the trick without the rest of the book.