title: 'git cat-file -p <sha1>': "fatal: Not a valid object name" on random objects from .git/objects
body: <p>I want to learn more about the inner workings of git so I ran these commands:</p>
  
  <pre><code>cd .git/objects/62
  
  ls
  00cb2f01089db22aca24675272a16712e89747
  0ee798881329430bfef6c558be7b14c1f0676f
  1087f408e2f2bd782d53a1211a7418fee4f6a7
  a6a71f3bd5a3af882f3f0ec4fad4c672055746
  f95e69f344b52c5038d922260189475626e69a
  
  git cat-file -p 00cb2f01089db22aca24675272a16712e89747
  </code></pre>
  
  <p>and got the following error:</p>
  
  <pre><code>fatal: Not a valid object name 00cb2f01089db22aca24675272a16712e89747
  </code></pre>
  
  <p><strong>Why did I get it?</strong></p>
  
  <p>I tried like 10 times (for different files from different directories inside .git/objects) and got the same error.</p>
  
  <p><strong>How can I view the actual content of the files (be it a blob, tree or commit)?</strong></p>