Choose the mountain you want to climb: don't pay attention to what other people say, such as "that one's more beautiful" or "this one's easier". You'll be spending lots of energy and enthusiasm to reach your objective, so you're the only one responsible and you should be sure of what you're doing.
Worry a little bit every day and in a lifetime you will lose a couple of years. If something is wrong, fix it if you can. But train yourself not to worry: Worry never fixes anything.
It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure.
First follow Nature, and your judgment frame
By her just standard, which is still the same:
Unerring nature, still divinely bright,
One clear, unchanged, and universal light,
Life, force, and beauty must to all impart,
At once the source, and end, and test of art.
If you are lucky enough to have lived in Paris as a young man, then wherever you go for the rest of your life it stays with you, for Paris is a moveable feast.