Make it work, make it right, make it fast.
Optimism is an occupational hazard of programming; feedback is the treatment.
The business changes. The technology changes. The team changes. The team members change. The problem isn't change, per se, because change is going to happen; the problem, rather, is the inability to cope with change when it comes.
Learning research tells us that the time lag from experiment to feedback is critical.
If you're having trouble succeeding, fail.
Of the four project development variables - scope, cost, time and quality - quality isn't really a free variable. The only possible values are "excellent" and "insanely excellent", depending on whether lives are at stake.