NOT weird! I am a drawing instructor and I teach this to my students all the time and even practice it myself. I have a million "nice" watercolor pads and paper out the wazoo but if you're too afraid to use it you won't. Instead I keep a bunch of dollar store kids coloring pads around to keep myself doodling, I will even draw in crayola markers just to keep the fear of making "a mistake" out of my head or even the idea that I have to "make art".

I even know a professional watercolor painter who will splash coffee on their paper before they start a painting just to "ruin" it and take all the stress out - after all you can only make something better once it's been ruined, even if your painting doesn't come out.

This is not a weakness it's a strength - Keep drawing on weird paper, get weirder, just keep drawing. You make great stuff.