We were taught what big O notation actually is, so yes. The whole point of big O notation, what makes it so useful, is that it hides information (namely constant factors). It's not supposed to "tell the whole truth," it's supposed to allow the analysis of algorithms not at any one runtime, but in an asymptotic mindset.

With big O notation, you're not interested in how fast an algorithm ever actually runs (for that is the realm of constant factors), but rather how its running time changes as the size of its input changes.