<ol>
<li><p>You weren’t taught from textbooks.</p></li>
<li><p>There wasn’t a need for step-by-step foundational learning: I’m speaking not only within engineering, etc, but of basic physics, mathematics, chem in your case, etc.</p></li>
<li><p>You were taught cutting-edge concepts within your field.</p></li>
<li><p>You were taught grad concepts and were obviously able to latch onto them.</p></li>
</ol>
<p>Care to explain, instead of giving a one-sentence answer? I’m not speaking of labs where the student is able to convey concepts in lectures to projects at hand.</p>