I once invited the entire class when I was mainstreamed (31 people) to my birthday party in elementary school. Three people came, two of them I didn't like. My mother claims the low attendance was because I had been out ill for two months, which may have been the case but I'm skeptical.
Another time, when I was mainstreamed for a few months in middle school, I made a few friends and even had a party but again became ill and during that time was removed from mainstream. None of the friends I had made contacted me. I ran in to one a number of months later and she told me they had wondered what had happened to me (it didn't occur to me to contact them).
More recently, I thought I had lost my contacts when I had to replace my sim card and they were not transferred to internal memory before the card was destroyed. I put out a message on Facebook explaining I had lost my contacts and to text me their numbers. No one did. In fairness, my "Facebook friends" consist of people overseas I didn't have numbers for anyway, cousins who routinely lose their phone accounts, immediate family who's numbers I have memorized and who I see regularly, a friend who never signs on to Facebook, former co-workers who's number I don't need and who don't need me to have their number, and co-workers who do need me to have their number...shame on them for slacking off. Anyway it turns out I had a backup on my old phone and written down in a notebook. There was a second friend who would have eventually texted me anyway.