Hhhm, I have been thinking more about why I have so many clothes. I am going to latch on to what Kristina said! My wardrobe can be split into four: work, casual, formal dinners and then dinner/date nights.
Work: I work in a formal office so have about different types of work clothes - trouser suits, skirt suits and then my new preferred style shift dress with matching jacket. I also have business casual for when I dress down (rare) or am at a conference. I have these in both autumn/winter and spring/summer versions. So skirt/trouser suits, I have long sleeved blouses for winter and camisole tops for summer. I also have coats for the different seasons and dependent on what suit I am wearing. Finally, I have shoes, bags, scarves, cufflinks and jewellery to accessorise. I buy designer or high end of high street - Austin Reed, Jaeger, Hobbs, LKB, Banana Republic, Ann Taylor etc for work.
Casual: This is mostly a uniform of t-shirts/long sleeve t-shirts, jumpers, cardigans with jeans and then summer versions. I tend to live in boots in autumn/winter and pumps for summer. I buy mid to bottom end of high street (eg Primark, Zara and M&S) for casual (except for shoes and bags) as its usually messy time spent with toddler and pre-schooler!
Formal dinners and weddings: I think I have about 30 different dresses, each only worn a handful of times, mostly from Coast. Accessories tend to be same as work but I have more "statement"/blingy accessories here.
Date night/kids free time: A mixture of dresses and tops and trousers. I have a different set of accessories to go with these. I tend to buy high end of high street (eg Phase 8, Kaliko) or designer.
Holiday: For some bizarre reason, I have clothes that I only tend to wear on holiday. Eg I have an Alberta Ferreti "jumper" that's never been worn in the UK!
I am not counting my maternity wear as have just packed that all up (that also split into work, casual and formal!).
Bugger, that looks a lot all written down.