You know how people have physical crosses, some hang on walls, some are small enough to carry in your pocket, or hang around your neck? Well, people who take things too literally will physically carry their cross. But what Christ meant was to follow His example no matter what kind of persecution comes your way. It might be an actual cross that you are nailed to, it might be imprisonment, it might be that one of your family members will no longer talk to you, but it is not a physical cross but a spiritual one.
In the same way, the mark of the beast is spiritual, not physical. On your hands means the things you do, and on your head means that you entertain evil thoughts that you plan to carry out. For example, let's say someone can't pay the bills so they consider prostitution- which their deeds carry out. They didn't allow their mind to be led by the Spirit- which would have reminded them of God's word that said, do not worry, just as God provides for the birds of the air, He will provide for His children. The price of bread may be outrageous (the price of living) but anyone who takes the mark of the beast for any reason will not go to heaven. there will be no excuse.
Now whether or not the government does make a physical mark to represent the spiritual mark, who knows? But God knows the thoughts and intentions of the heart (mind), and anyone who listens to the beast, who wants to make your thoughts like his thoughts, will not be one with God forever.
It doesn't matter what scar you have on your physical hand. Physical hands and physical brains are going to be destroyed along with this physical earth. Your soul is what you need to concern yourself with.