There cannot be mental atrophy in any person who continues to observe, to remember what he observes, and to seek answers for his unceasing hows and w… - Alexander Graham Bell

Don't keep forever on the public road. Leave the beaten track behind occasionally and dive into the woods. You will be certain to find something you have never seen before, and something worth thinking about to occupy your mind. All really big discoveries are the result of thought.

The inventor...looks upon the world and is not contented with things as they are. He wants to improve whatever he sees, he wants to benefit the world; he is haunted by an idea. The spirit of invention possesses him, seeking materialization.

What this power is I cannot say; all I know is that it exists and it becomes available only when a man is in that state of mind in which he knows exactly what he wants and is fully determined not to quit until he finds it.