Are you upwardly or downwardly mobile? Upmystreet.com is insidiously fascinating and horrible at the same time. You can use it to see what your postcode says about you - it'll even tell you what foods you buy and whether you watch ITV a lot. Spy on your friends before visiting them, to decide whether or not it'll be safe to park your car outside their home. I entered all the postcodes I've ever lived at to see what it had to say about me:

Aged 1-18 Type 41: Better-Off Council Areas, New Home Owners

Aged 18-21 Type 44: Multi-Occupied Terraces, Multi-Ethnic Areas

Aged 21-25 Type 37: Multi-Occupied Town Centres, Mixed Occupations

Aged 25-31 Type 3: Mature Affluent Home Owning Areas

I'd agree with affluent (just), but mature? Surely not.