To thy own self be true.
Chapter XXIII
If you ever happen to turn your attention to externals, for the pleasure of anyone, be assured that you have ruined your scheme of life. Be content, then, in everything, with being a philosopher; and if you wish to seem so likewise to anyone, appear so to yourself, and it will suffice you.
Thoughts
a. To thy own self be true.
b. Externals are events, items, status, power or personal gains which are not in your control.
c. Desire or avoidance of externals not in your control, but in the gift of others, leaves you in the control of others.
d.Desire or avoidance of externals not in your control, leads to you be subservient. A slave.
e. You relinquish your freedom to others by desiring or avoiding externals.
f. You only have to please yourself not others to be content.
g. Do not try to influence or impress others with being a philosopher. Practice humility and do not be arrogant and/or haughty.
h. Last sentence is not completely clear to me.