Some men never seem to grow old. Always active in thought, always ready to adopt new ideas, they are never chargeable with foggyism. Satisfied, yet ever dissatisfied, settled, yet ever unsettled, they always enjoy the best of what is, are the first to find the best of what will be.
The scientific theorist is not to be envied. For Nature, or more precisely experiment, is an exorable and not very friendly judge of his work. It never says "yes" to a theory. In the most favorable cases it says "Maybe," and in the great majority of cases simply "No." If an experiment agrees with a theory it means for the latter "Maybe," and if it does not agree it means "No." Probably every theory will some day experience its "No" - most theories, soon after conception.
For the young people here: practicality is a good thing. There are times where compromise is necessary. That's part of wisdom. But it's also important to hang on to what you believe.