The joy of sales

Today I got a knitted fleece, a weatherproof fleece, and a fleece-lined goretex jacket all for £80.  I haz a warmz.  Slightly disconcerted that I now take a size 14 in outdoor jackets.  I don't mind, but it's weird.  I'm 9½ stone just now, at my heaviest I was 11 stone, yet at 11 stone I took a size 10 and at 9½ stone I take a 14.  How in the hell does that make sense?!