Couldn't agree more. 99% of the time I feel blocked, frustrated, etc - I pick it up and read (almost at random) and it also helps reset mindset. This in particular is one of my favorite passages:
"Never let the future disturb you. You will meet it, if you have to, with the same weapons of reason which today arm you against the present."
"Never let the future disturb you. You will meet it, if you have to, with the same weapons of reason which today arm you against the present."