Once upon a time Jesus healed ten dudes with some serious health problems and only one of them returned to personally thank him. Jesus was a little “surprised” by this. [Luke 17:17] “Were not all ten cleansed?” Jesus asked. “Where then are the other nine?
If someone's heroic actions saved your life it would probably be good to express your thanks in some way. Like buy them a large Snickers or something. This world we live in would be a much better place if we all got better at thanking others. And even more important than thanking people, is remembering to thank God for those who have been a blessing in our life.