When I was a very junior software engineer working on Fortran 77 signal processing modules on MicroVaxes, PDP-11s, Masscomps and old 286 PCs I was given some very wise words by the owner of the company: "Assume nothing". This has stuck with me for nearly quarter of a century. It is pithy, easy to remember and is so true for software engineering.
1. "Assume nothing" makes me look up details when I'm not 100% sure.
2. "Assume nothing" means that I double check my facts when I think I'm 100% sure.
3. "Assume nothing" makes me question even the so called 'obvious'. "Of course it will work.." turns into "are we sure it will work for every possible case?"
4. "Assume nothing" makes me dot the i's and cross the t's.
5. "Assume nothing" keeps me sceptical, which is useful as there is a lot of stupidity masquerading as knowledge on the internet.
I could ramble on. However enough said. Just assume nothing, it will keep you out of a lot of trouble.