Yep, you have a misunderstanding.
As a rough example, a solar PV panel is like a battery. Resting voltage of a 12V lead acid battery is around 12.7V. However, as soon as you start drawing power from it, the voltage sags down a bit. The more amperage you pull, the farther it sags. The same goes for solar PV panels. The more you try to draw from them, the farther the voltage sags. That is why we have MPPT controllers. The MPPT controller trys to balance the load on the panel to get the most wattage out of the panel.
That being said, you're probably better off with your panels in series than parallel. Higher voltage will increase the efficiency of the system, and your MPPT controller can handle the higher voltage.