Overwhelming gratitude

That is what I feel for the life I have. I feel thankful to have God to thank for this, if that makes sense. I sometimes wonder what people who don't believe in God do when they feel overwhelming gratitude. I think everyone who is a parent has felt this, feels this often. So who or what do non-believers thank when they are feeling grateful? Or am I strange that I feel the need to thank someone at all? I don't know the answer to either question, but to me it feels right to thank God for my blessings at the same time as I pray for others. My heart is full.