Based on the meaning given(by our mind) to the experience we feel happy or sad about the experience. The object(environment) is very little under our control but the meaning given by us to the experience is totally in our control. We need to be aware to give the meaning we want which will empower us, otherwise the meaning would be given by default, based on our past conditioning, likes & dislikes. If the meaning is given without our awareness(by default) we can't be sure whether it will empower or dis-empower us.
When we see any object we see not only the object(the substance) but also its attributes like colour,shape etc., though we perceive this as a unitary experience(since the object and the attributes have the same locus) in reality it is a binary experience that is the experience of the object and that of its attributes. For example if you see a green colour pen, you are not only experiencing the pen(the object) but also its green colour(its attribute). All objects have one common attribute which is the Existence - the "isness". The pen is there. with respect to external object the "isness" is known as Attributive Existence & with respect to our internal thoughts it is known as Consciousness. The Existence & the Consciousness is part and parcel of our true self. This knowledge gives us freedom. Attributive Existence is perceived by our senses and Pure Existence without any attributes can't be experienced by our senses.
Pure Existence is the Oneness without any Second.