The right subject to study, the right school, the right career, the right job, right person for the job, the right product, the right marketing strategy, the right branding, The One.
Why? It stops you looking for anything greater.
So even if you think your work, business or life is ticking along very nicely now, and you don't feel stuck or limited by anything, ask "If I didn't do it this way, what other ways could I do it?"
This is an invitation for greater awareness. Especially if you're in business. Questioning the things you think are perfect can make you an industry leader and innovator.
And if you do end up choosing to do things the same way as before, it will be because that is still the most inspiring option. Not because you were stuck in a rut.