The answer to this question is quite subtle in that it depends upon the context of the situation, which is to say, that an attack may take many forms.
Broadly speaking, attacks on your person may be broken down into two categories: physical and mental.
A physical attack will usually involve another person applying an inappropriate amount of force on a part of your body (they may, for example, push their fist quite firmly and quickly into your face). You will know when this happens because it will be quite painful, if done properly.
A mental attack is an altogether different beast as it involves another person attacking your psyche. Generally the attacker will use words or actions to damage your ego. The net result of this is that, due to their actions, you will feel sad, or worse yet, you may even begin to sob uncontrollably, much as one imagines David Hasselhoff does when he looks in the mirror and sees quite how awfully he has aged.
There are other forms of attack which are not directed at your person but may instead be focused on your property, legal rights or friends and families (although, technically speaking these are attacks on you 'by association'). Perhaps you can explore these possibilities with a good enemy or personal nemesis?