It's tricky to learn that in RPN. It's nice to be able to go back to algebraic mode on the HP calculators in rare situations where you do not know the right syntax (which can be arbitrary by calculator) for entry of equations.

It took me about a month to learn RPN along with equation entry, and I did that while in my weed-out courses in engineering school. Everyone was using a different calculator than me, and while they could directly learn from each other, I had to figure out how to enter stuff on my own. But, it paid off on exams, as people who made parenthesis or entry errors got major points off. It also saved time on exams and I really did not have to double check for entry errors, which can be quite tedious on electrical engineering exams.