Compression is hard to grasp when you have no vision about where exactly you're intending to musically regarding either a particular instrument or the whole mix bus. Compression is supposed to aid a vision and either serve as a solution or increase the intelligibility of a particular instrument, bring it forward, send it backwards, smoothen it up, make it snappier, etc. Ask yourself what you actually want from a sound/instrument before you even open the compressor. If you know exactly what your vision is, compression is easy to grasp. A compressor is hard to grasp when you just load the comp as a habit/tendency on a track for the sake of it without pre-deciding what you're actually looking for sonically.