Not embarrassing at all. Games expose both and explain neither, so almost everyone adjusts them by guesswork.
Deadzone is a starting threshold. It decides how far your stick has to move from centre before the game registers anything at all. Below the threshold, nothing happens. Above it, input begins. It exists to stop a stick that does not rest perfectly at zero from causing unwanted movement, and the correct value depends on your controller, not on your taste.
Sensitivity is a multiplier. It decides how much happens for a given amount of stick movement once the deadzone has been passed. Higher sensitivity means your view turns faster for the same push. It exists to match the game to your preference and your screen, and the correct value depends entirely on you.
That difference tells you which to change for which problem. If your aim drifts when you are not touching the stick, that is a deadzone problem. If the stick feels unresponsive for the first part of its travel, your deadzone is too high. If aiming feels too slow or too twitchy once you are moving, that is sensitivity. People commonly try to fix drift with sensitivity, which cannot work, and try to fix slow aiming with deadzone, which only removes precision.
The order to tune them matters, and it is the useful part. Set the deadzone first, from measurement rather than feel: run a deadzone test, note your resting value, and set the in-game deadzone just above it. That is a number, not an opinion, and it should be the same across every game. Then tune sensitivity by feel, over a session, changing one value at a time. If a response curve is also offered, set that after sensitivity, since it changes how sensitivity behaves near centre.
Do that once and every new game takes thirty seconds, because the deadzone is already decided and only sensitivity needs matching.
