We trust people based on our current situation.
Here's what happened to me:
A few months back, a close friend of mine ratted me out. I had total trust in him that he won't say a thing. Unfortunately, he did.
After this incident, I thought I could never trust him again with any of my personal matter.
But here's the kicker:
I started trusting him again. Maybe not because I forgot everything and wanted to have a fresh start but because trusting him again was the only profitable option.
I could have what I want by having faith that he won't rat me out anymore and taking the risk.
Life is risky and trust indeed is situational.
One day you trust someone, the next day you don't and then you start trusting them again.
It all boils down to what situation you're currently in and what seems like the best thing to do at the moment.