Describe a personal rule that you try to live by

A personal rule that I try to live by is never to promise anything I'm not sure I can deliver. It sounds simple, but it has had a big influence on how I deal with people.

I came to follow this rule after a rather embarrassing experience at school. I was about fourteen, and I had told a classmate that I would help him with his history project over the weekend. In the end, I had a family event and forgot completely. He waited for me for two hours at the library and, on Monday, had to hand in an unfinished project. He wasn't angry, just disappointed, and that was worse. I realised that a careless promise can damage trust far more than an honest refusal.

Since then, I think carefully before I say yes. If a friend asks for help, I check my schedule first, and if I'm not certain, I say something like, 'I'd like to, but I can't guarantee it. Let me confirm tomorrow.' If I do commit to something, I write it in my calendar and treat it as seriously as an exam. At university, this habit has made me a reliable team member, because people know that when I say I'll finish a section by Friday, it will be ready.

This rule matters to me for a few reasons. Firstly, it protects relationships, because people can depend on me. Secondly, it reduces my own stress, since I don't overload myself with obligations. Thirdly, it builds self-respect: keeping my word makes me feel that I'm a person of integrity.

Of course, I sometimes make mistakes, but I try to treat the rule as a standard I hold myself to every day.