Word for "feeling the same as someone"

What is the word for when you feel the same as someone, you see them in yourself or you are in the same situation?

I think it starts with the letter C.

You may be trying to think of commiserate, but I think empathize is a better fit.

Empathy [ˈɛmpəθɪ] n

1. the power of understanding and imaginatively entering into another person's feelings
2. the attribution to an object, such as a work of art, of one's own emotional or intellectual feelings about it

[from Greek empatheia affection, passion, intended as a rendering of German Einfühlung, literally: a feeling in; see EN-, -PATHY]

Compassion may be the word you're thinking of. Someone who has compassion is sensitive to the feelings of others:

Deep awareness of the suffering of another, coupled with the wish to relieve it

However, compassion does not necessarily mean one has been in the same situation. Empathy may more strongly convey the meaning you want, because it usually means that you can imagine yourself in another's shoes, or if your empathy is born of experience, that you have gone through the same hardships. Someone with empathy has:

capacity to understand another person's point of view or the result of such understanding