I find it surprising that logarithms and e (a.k.a. Napier’s constant), were developed and discovered only relatively recently in the history of mathematics despite how natural and fundamental they are.
The idea of exponential growth and the practice of charging interest in finance are both ancient. Surely an ancient mathematician would have investigated these in depth and discovered what Napier, Bernoulli and others found?
A while ago I was solving several infinite series of exponentials in the context of a problem concerning the half-life of medicines and I made frequent use of logarithms. That is when I started to wonder about their history.