My Adult Coloring Book Habit

I know it sounds like a childish thing to do, but I'm in my 40s and absolutely love coloring books. Whenever I need to relax or escape from work stress, out comes the set of intricate mandala designs and my best fine-tipped markers. Don't get me wrong, I'm not sitting there with crayons scribbling like a kid, these are high-quality art supplies, and I take it seriously. But there's something incredibly soothing about getting lost in those patterns for hours on end. It's almost meditative, and by the time I look up from the page, my troubles seem to have faded away. I've noticed this isn't a common hobby among my peers at work or during social gatherings. We joke about 'the old guard' sticking to golf and gin rummy for their relaxation activities, but honestly, those don't appeal to me as much anymore. Is it normal for adults in their 40s to enjoy coloring books, or am I just a bit quirky? What do you all think?