If it works for you, than it's good...and you aren't an idiot :).

The key difference to understand is that the shape may be the same, but the roots are in different places. So you can't play the scale the same way for C as you would for Am. It's the INTERVALS that give the scale its sonic flavor, not the notes themselves.

You could take it a step further and say that with one single scale pattern, you have all 7 modes down. The minor scale is just one of those modes. Each mode of a scale is the same notes, just starting from a different point in the scale...it's the intervals.

The pentatonic scales work in a similar fashion. Take a minor pentaonic scale shape and slide it back 3 frets...and you have the major pentatonic scale for that key. Pretty handy!

Here's how this can actually be useful. I started out learning all of the minor pentatonic shapes and that's how I solo. That's currently my frame of reference. So let's say I'm soloing in a song that a major pentatonic scale fits best in the key of G. I notice that this would use the same scale shapes as Em pentatonic. So I use those shapes and think "Em", but start on G rather than E to get my "center" and my ear takes me the rest of the way.

Not saying that is the best way (probably not actually), but it is A way.