Man never realizes how much customised distribution he has until he has to reinstall it. Last week hard disk in my notebook died, so I had to reinstall system and reconfigure everything. I fortunately have backups of almost everything (at least I didn't notice that anything would be missing), but I anyway spend two evenings in installing, configuring and restoring from backups and I'm still not done with it, but the system is at least usable for normal work.
However there are also some positive things on this: I get more space and faster disk. I finally set up encrypted file system on my notebook. I dropped several old crap that lived (or better was buried) somewhere in my system and which I already forgot why it was there. And I also got rid of very bad partitioning scheme, which was there from times I used together Debian and Windows and wanted to have another partition to test SUSE installation while I worked there. Now there is only Debian to rule them all ;-).
