Why do people kiss their thumbs after making the sign of the cross? I've always wondered that! Thanks!Well, after the sign of the cross, some people make a cross with their thumb and index finger--your thumb is the vertical bar placed over your index finger, which is the horizontal bar--and then kiss this cross. In so doing, you are not just kissing your thumb, your are symbolically kissing the cross of Jesus. It is a sign of love and respect for what Jesus did to save mankind, just like the sign of the cross that the person has just performed.