We tend to gravitate toward exercises and stretches that we're familiar with and feel comfortable doing. The problem is your body most likely needs more than this in order to be pain-free and stronger. Your brain which controls bodily movement has learned to move a certain way in order to avoid pain. The problem is that this "certain way" of moving may not be conducive to your health and well-being. You've subconsciously learned to move in a way to avoid pain for better or worse. The end result: your brain has learned to process an abnormal movement as a normal movement as a means to prevent pain. The idea here is to step out of your comfort zone that your brain (and therefore your body) has adapted to for such a long time. The unfortunate aspect of training from one day to the next is that you most likely do not realize you're exercising within your comfort zone. You've become so used to training a certain way that your body has learned to adapt to an abnormal movement pattern. Remember, adaptation is the enemy of progress. A knowledgable personal trainer and/or a physical therapist may be an invaluable resource for you to realize and then learn how to break away from a faulty movement pattern that may be causing chronic muscle pain.
BOTTOM LINE: In addition to performing exercises you like such as the bench press (which precipitates anterior shoulder tonicity), be sure to include exercises you need such as the pec-dec flye (which encourages anterior shoulder flexibility) as well. In addition, be sure to work the core muscles (e.g., glutes, abdominals, lower back and hamstrings) of your body to lessen possible muscle imbalances which may precipitate joint pain and injury. Strengthen weak muscles (typically upper back, abdominals, hamstrings, glutes and abdominals) and stretch tight muscles (typically anterior shoulder, chest, abdominals, lats, lower back, hamstrings, hip flexors, and calves). Heeding this advice will save you years of needless chronic pain due to muscle imbalances.