What are your "triggers"?

I was telling my therapist how I still feel extremely lonely, despite my efforts to try and make new connections. Basically, after months of trying everything to make friends, nothing has worked. All he said in return was "it gets better." I immediately got this deep feeling of rage inside me but I didn't say anything. Hearing the phrases "it gets better" and "be your own best friend" definitely trigger the worst feelings for me, as well as seeing people with their friends out in public.

What are some of your triggers?