Leave the beaten track behind occasionally and dive into the woods.

Watson, ... if I can get a mechanism which will make a current of electricity vary in its intensity, as the air varies in density when a sound is passing through it, I can telegraph any sound, even the sound of speech.

When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.

With every door that closes a new one opens.

Another discovery which came out of my investigation was the fact that when one gives his or her order to produce a definite result and stands by that order, it seems to have the effect of giving one what might be termed a second sight which enables him or her to see right through ordinary problems. What this power is I cannot say; all I know is that it exists and it becomes available only when one is in that state of mind in which he or she knows exactly what one wants and is fully determined not to quit until he or she finds it.

Before anything else, preparation is the key to success.

First words on the first telephone - "Mr. Watson - come here - I want to see you."