"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell
In these days where any internet forum on any topic can tell you exactly what you ought to think, it takes some doing to separate bombast from insight. The thin veneer of "everyone told me I'd love these wheels (this helmet, these pedals, this size of bike, this pro-looking saddle to bar drop)" is just that - a thin veneer. You only get so much time on your bike, and every ride during which you use less than the best setup you could, given whatever resource restrictions you've got, is a missed opportunity to have had more fun, gone faster, or been more comfortable.
People who know me best might well describe me above all else as an anti-dogmatist. They would likely soon thereafter describe me as long-winded, which makes perfect sense. Every time I get involved in a topic, it's like one of those old make your own adventure stories. Each door passed through leads to subsequent decisions that go further and further down a road particular to your situation, and away from any universal "this is the best." So many people have it in mind that they want "THE best bike (wheels, tires, etc)" rather than the best bike (wheels, tires, etc) FOR ME." Small change, big difference.
Listen to, or read, how people phrase things, and how they legitimize their information. Statements like "I put these wheels on and beat my old personal best on my 10 mile loop by 4 minutes" have a tendency to see me very sharply question whatever else that person might have to say. I recently felt like I had to justify some acuity that I claimed to have regarding wheel performance, which I thought I effectively did by explaing that I've ridden the last 15,000 or 20,000 or so miles with a sometimes burdensome awareness of my equipment. There really is no "just go ride" for me anymore, and I have the luxury of being able to think I'm feeling something, and make a considered equipment change relevant to that facet, and fairly effectively either validate or dismiss that feeling.
I'm far from saying that you have to sentence yourself to this lifetime of acute awareness to what's going on - a ton of the enjoyment that people get from riding and racing is in just "going with it" and tuning a metric ton of other stuff out. What I am saying, however, is that everyone who will read this probably spends more than enough time in the saddle to develop a very useful awareness of your equipment in what is a pretty equipment-relevant activity.
The better you arm yourself with awareness of what equipment does and doesn't do for you and the people in your context, the better capacity you will have to select and manage the equipment that is going to be the most beneficial for what it is you want it to do.
Become your own expert.
Dave – thanks for these well stated observations. Using a little "critical eye" as you suggest allows one to easily sort through the wheat vs. chaff in what sometimes passes for dialog on the interweb.