I'd like to see you explore a topic that there's not a lot of information on already. With a time management book you'd have a lot less to add because that topic is so saturated. With subjective reality or polarity you'd be covering new ground so you'd have a lot more to add because there's not a wealth of knowledge already out there on those subjects.
You're right about both topics being possible commercial flops, but since when do you care about that??
Maybe you could publish books on subjective reality and polarity in an e-book format so you don't have to charge commercial publisher prices..?