There are good reasons not to believe in free will, unlike the reasons to believe in free will which boil down to 'i feel like i have it'.

1. Brain activity related to making a decision occurs in a predictable pattern in a predictable part of the brain several hundred milliseconds before the person reports having 'made a decision.'

2. Self-control (i.e., 'free will') can be compromised by brain damage - if damage occurs in the premotor cortex, 'alien hand' syndrome results which essentially means the person loses control over one hand. If damage occurs in the prefrontal cortex, the loss of will is more general, and the person has difficulty making decisions.

3. Karl Pilkington sums it up.