emotional impact of being retrenched

my ex-colleague (also retrenched) totally ignored my emails and SMS.  I was wondering if his retrenchment had so much adverse impact on him that he wanted to disassociate all his bad memories, including his ex-colleagues. But i do have another ex-colleague who i keep constantly in touch, encouraging each other and sharing any employment opportunity. i have yet another ex-colleague who was constantly seeking advice from me while being retrenched, but hardly contacted me again after he found a new job. It made me feel "used" because i had been helping him when he needed help but he failed to return any favor when he is in a better position to do so.