The broken thought-process there is mostly about when you take a shotgun approach that involves many different things that could all individually pan out (or not); or which could all be multipliers for one-another (or not.) If, in the end, you succeed, you end up believing that everything you tried was a necessary part of your success. When, in actuality, you might have succeeded despite some of those approaches, rather than because of them. They might have been actively harmful to your success, but just not harmful enough to overcome the other successful things you tried.

In another instance, people who try one main thing (e.g. applying to a particular college) but who succeed entirely through no effort of their own (e.g. through nepotism), will end up thinking that what they did mattered.