People usually don't experience grace unless it hits them over the head with some big miracle. They aren't in tune with the constant little miracles weaving in and out of their lives every day; miracles like breathing and seeing and hearing and walking and talking and thinking and being able to feel. That's why so many spiritual paths promote the concept of gratitude.
It helps you notice the grace in your life. I always found the act of saying "thank you" more useful than trying to be grateful. It's a lot easier to say a couple of words than to try and force yourself to feel something you may not be feeling. "Thank you" is a high message, possibly the most healing message of all. "Thank you" aligns you with the grace that comes from the Universe of soul.