> If "your code" is like "most code" you'll be happy to leave it behind.
> Hopefully writing it has made you a better programmer. I wonder why the
> house painter doesn't feel such attachment to the paint she leaves
> behind at her previous job; or the lawyer to the contract written late
> at night; and of course the manufacturing worker seems to not have
> access to that which was manufactored.
Because software is a *tool*; you can use it to build other things. So some of what I have produced can be reused and re-purposed. A paint of coat is a paint of coat and that's all you've got, but software can be copied at no cost and modified. Certain well-written software (admittedly a rarity) is a lot closer to being a factory that can create custom paint and custom painters.
A free software library I have worked on is used by Apple, VMWare, Lucasfilm, and a myriad of small companies and open source projects; every other time you buy an airline ticket online in the US you are indirectly relying on this software. Yes, the software all these users have written is often completely task-specific and not useful to anyone else, but the library is general purpose.
As another example, one of the defunct open source companies I mentioned left this behind, still actively maintained: http://allmydata.org/trac/tahoe