title: see all history of git
body: <p>Let's say, my current git log is </p>
  
  <p>commit3</p>
  
  <p>commit2</p>
  
  <p>commit1</p>
  
  <p>I reset the head to commit2.</p>
  
  <p>Now I want to go back to commit3, but I <strong>forget</strong> the sha-1 of commit3, so I want to look at the log , but "git log" will only show commit2, commit1, my question is how to reset to commit3 or let the log show also commit3 now?</p>
  
  <p>Thanks</p>