I've been thinking about this. I do shop a lot for things I need, mainly online - like cat food or a new cake tin or whatever, and enjoy that too.
But for clothes, and also craft and sewing stuff, it's really about an endless quest for things that make me feel "right" and express myself and meet my cravings for design and textiles. It's not really fashion (although I like fashion magazines so I'm probably influenced by them), it's about those perfect things that are easy to wear and feel right, but they are hard to find and I make mistakes.
But then I do also find them and they bring me a lot of happiness, so I live in hope.
Like a PP I enjoy getting into a particular idea or look and looking and researching for the best option - which also means I can spend quite a while "shopping" without spending, which is a bonus.
With fabric, I have a dream of creating a particular thing, find the fabric and buy it, but then get another obsession before I have time to make the first thing
resulting in a large stash.
On the positive side, I love ebay and charity shops, and fabric is usually cheaper than clothes, so my spending isn't too crazy. I do shop too much though.
One problem is I'm a single mum, rarely go out and it's really hard to do a lot of stuff like creative hobbies, reading or going to the gym, with DC around. But it's easy to sit on my ipad and browse ebay so I tend to default to tat.