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.
I was always wary of using drugs to solve my problems (I always thought I should just apply more willpower), but then my anxiety got so bad that I cried every day for nearly a year. Going on SSRIs immediately made a massive difference. I only cry about once a month now and have far more good days than bad.
Similarly, sucking it up and taking ibuprofen when I feel a migraine starting is way better than 'powering through' it. You requested only one problem-solution pair per answer, so I'll generalize this to 'significant life improvements when I stopped blindly rejecting drugs on principle.'