Earlier quoted context omitted.
This may be difficult to hear, but something is wrong if you have been working for 20 years and old colleagues aren't occasionally checking in to see if you'd like a different gig at their current company. The people who called you a miracle worker, they don't keep in touch? They don't want you to join their current project? You may want to ask someone who you are on good terms with what's going on.
This is insulting and just flat out unrealistic. If you've had this experience, great, but what you're describing is very far from the norm.
Working somewhere for decades and not being in touch with a single colleague is not normal. Imagine hearing "I didn't keep in touch with a single person from my 16 years of primary + university education after school ended."