&gt; First, there is your biology. You might simply not be intelligent enough to become a great engineer.<p>Biology is overrated. From &quot;You and Your Research&quot;[1] by R.W. Hamming:<p>&quot;You observe that most great scientists have tremendous drive. I worked for ten years with John Tukey at Bell Labs. He had tremendous drive. One day about three or four years after I joined, I discovered that John Tukey was slightly younger than I was. John was a genius and I clearly was not. Well I went storming into Bode&#x27;s office and said, &#x27;How can anybody my age know as much as John Tukey does?&#x27; He leaned back in his chair, put his hands behind his head, grinned slightly, and said, &#x27;You would be surprised Hamming, how much you would know if you worked as hard as he did that many years.&#x27; I simply slunk out of the office!&quot;<p>Other anecdotes lead me to believe the primary difference between those that are and those that might have been is hard work.<p>&gt; You might not have the health and the endurance to work on demanding high-end projects long enough to get really good at those kinds of projects.<p>Bad health is a rough deal for anyone. But it is possible to succeed in the face of it. Look at Goddard[2]. There&#x27;s a good argument that he didn&#x27;t reach his full potential because of his health, but he still did some truly great rocket science.<p>&gt; Your other obligations, like raising children, can get in the way<p>Rather than get in the way, I think they are often essential. I imagine it must be hard to do great things if you&#x27;re personal life isn&#x27;t in good shape.<p>There are real obstacles to &quot;greatness&quot;, I think. Things like access to education and financial security. But I find it hard to believe that biology, health, and domestic life are enough to stop a dedicated person from performing great feats.<p>[1]: <a href="http:&#x2F;&#x2F;www.cs.virginia.edu&#x2F;~robins&#x2F;YouAndYourResearch.html" rel="nofollow">http:&#x2F;&#x2F;www.cs.virginia.edu&#x2F;~robins&#x2F;YouAndYourResearch.html</a>
[2]: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Robert_H._Goddard" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Robert_H._Goddard</a>