[2rsf]

I never had this problem before and I switched positions in the same company more than once, in different companies. I think the companies I worked for fell under one, or both, two categories- big companies or good engineering culture.

If a company is big enough you simply get too detached from your previous projects, you might be asked for help here and there but the distance (physical, mental and managerial) will make it harder and harder to actually be productive.

The other type of company understands that it is not sustainable to keep a system maintained by someone with no commitment or dedicated time and will insist on a proper handover to a new owner.