An object moving at constant velocity has zero acceleration. Such an object changes its position uniformly. An object having constant acceleration increases its velocity uniformly. One is most aware of their motion when they are accelerating. In fact, within a smoothly moving train or car traveling at constant velocity if one were to shut their eyes they would not be able to distinguish their state from sitting at their breakfast table.
Accelerated motion is, on the contrary, quite different.
While in a car or train that makes a sudden stop we are thrown forward we feel a force pulling us forward. Such phenomena do not occur while sitting at the breakfast table. Another case of acceleration occurs when one deviates from straight- line motion for instance while rounding a corner. In such case one feels a force pulling them outward.