We didn't lie to you, but we weren't completely honest either. Its just a lot easier to pick one way to do things and stick to it than it is to explain all of the possible approaches with their tradeoffs.
You're starting your second job now and its going to be one of the most interesting times in your career. Its when you discover that there truly are an infinite number of ways to accomplish the same task. You'll probably find out that you have a pretty good handle on what to do, but not necessarily why you ought to do it that way.
Don't be too dogmatic. This is a tremendous opportunity to learn, both about new ways of doing things and also about the strengths and weaknesses of the approaches that you've been using. When you find yourself thinking "OMG, what the hell is this?", pause for a moment and try to figure out what the tradeoffs are: what could be some advantages to doing it this way? And ask a lot questions: "I see that you're using [tool A] instead of [tool B], why is that?" Maybe they'll have a g