Left or right side?

Until now I am still confusing when walking on the public places. Such as sidewalk, mrt stairs , underpass or shopping centre.
When I walk at the left side, the opposite will walk at their right side, so I have no choice has to move to right side... and vice versa. Noticed for some places, they put a sign "keep left side during peak hours", but peoples still walk at the right side.

When I look at the road, cars will be at the left side of the road, by right when walking should be at the left side too??

Am I the only one that confusing here?