Yes! Mine is like “big question” stuff. Philosophy, religion, psychology, etc.
There’s an inexhaustible amount of ideas to explore, so there is some variability. But as much as I read, I have not read fiction in like 20 years. No other hobbies, etc.
Luckily I found my way to psychology so I can practice in that area (mainly with struggles I have been through from the inside-out) and even provide “consultation,” i.e. getting paid to have a willingly captive audience listen to me info-dump about my special interest.
Mu hu ha ha ha.