It’s like a martial artist learning a new discipline, like boxing or aikido; his martial art may include some punching techniques and throws, but fighting “with new rules” helps him focus on specific aspects, like distance, rhythm, balance etc.

In PLO, a good hand on one street can often become a mere bluff catcher one or two streets later, and conversely when you are behind you very often keep some kind of equity that you don’t want to relinquish too fast. This sets new dynamics (eg. in pot-size management) that can take some time to get used to.

NLHE puts more emphasis on attacking villain’s range when it looks like it cannot stand the heat, whatever we hold; I would say there is more sheer aggression and bold bluffs in NLHE.

But naturally the same fundamental principles govern both games, and looking at them from two different perspectives help to develop a better understanding of how they apply.

I will also add that learning PLO will help the NLHE player come up with new ideas that he can incorporate into his NL game as well. There’s something about it that makes you look at things in a different light.

Maybe it’s because you’re just not used to it yet.

As a note aside, I believe NLHE players would benefit a lot from playing some PLO, as the differences between the two games force the player to think about the hows and whys of various things (eg. pot-size management) in greater details.

Too often, players will find themselves in spots where they don’t have enough money left to pull off an effective bluff.

The problem is just as you stated: “…you should manage your stack adequately to make the most of it.”

They really do need to think ahead.