Number Changes eg user numbers & post numbers

Has anyone noticed that their user number has changed,& also the numbers for old posts has changed, though clicking the old link seems (so far) to get to the right number

Yes notice that. Basically as far as I can tell moving to the new site has involved regenerating the database (and hence all the numbers) but functionality has been retained so that URLs from the old site redirect to the new one.

Yes, but couldn’t fathom it out.
Swapped identities then…
From your (Chris) 6257 is now one charles poole (pooley)
to 5824 - you (Chris) proper
I was 23029 who is now Cindy Lawes (Lemonytwist)
now I am 21890
Many of my saved links have been crashing for a while
As I said, hard to fathom…

This goes much further: As it is the second change in a relatively short time, the links for older observations before the first change do no longer work. Then the links from … back to iSpot are broken and have to be reworked. So every time such a change is made it necessitates a lot of work and time to get that whole web of links operating again.
Is it very difficult to retain those numbers / addresses?