What is your reason why?
True love is demanding. Instead of an one-time exchange of items, true love is a life-long gift of self. So when Jesus wants to know where your heart is, it is not because He is demanding from you something He is not already giving. Jesus has given His WHOLE Being to you, His Heart. Sound too good to be true? Look at Jesus on the Cross and try to deny it. His Heart was pierced with love for us.
So, will you give your heart to the God that gave His Heart for you? It sounds demanding, and it is. But God has already done His part. Will you receive His Heart by giving Him yours?