I read a lot of this type of stuff back in the 1990s. Your “purpose” doesn’t need to be spiritual or altruistic or even helpful to others, all that is necessary is that it keeps you from dwelling on yourself and your own problems> Serious study, if it is interesting enough to you and difficult enough to really engage your attention is more than enough to gain you the benefits of a “purpose”.
I read a lot of this type of stuff back in the 1990s. Your “purpose” doesn’t need to be spiritual or altruistic or even helpful to others, all that is necessary is that it keeps you from dwelling on yourself and your own problems> Serious study, if it is interesting enough to you and difficult enough to really engage your attention is more than enough to gain you the benefits of a “purpose”.