How do you trust your feelings?

Cindy: What did it feel like when you fell in love?
Gramma: Oh... oh dear, I don't think I found it
Cindy: Even with grandpa?
Gramma: Maybe a little, in the beginning. He didn't really have any regard for me as a person. You gotta be careful with that. You gotta be careful with the person you fall in love is worth it... to you.
Cindy: I never want to be like my parents. I know they must've loved each other at one time right? To just get it all out of the way before they had me. How do you trust your feelings when they can just disappear like that? Gramma: I think the only way you can find out is to have the feeling. You're a good person. You have the right to say I do trust. I do trust myself.

Blue Valentine (2010) by Derek Cianfrance