Earlier quoted context omitted.
About 10 years ago, I too, as a newbie-layman, started with "Predictably Irrational". I recall being similarly fascinated, and recommending it to anyone who'd listen to me. It's surely a gentler start to the field; and I concur with you on suggestions for deeper material.
Nudge is pretty easy reading from Thaler and Sunstein. Personally tough, I preferred his Misbehaving which goes into his history with the field. Way back when, I had a couple courses with Thaler when he was calling the field Behavioural Decision Theory.
Thanks for the 'Misbehaving' recommendation.