Yoga and several other eastern philosophies are built around the concept of the wheel of karma and samskara.
Karma is action. Samskara is the imprint of the action: the unresolvedness of the action.
POTHOLES, a metaphor
Where I grew up there were still a few dirt roads left. I'd often see in these dirt roads these strings of potholes, decreasing in size. As I looked at them I deduced which was the initial pothole, the first and largest - it's cause unknown, perhaps a puddle. When cars hit the first pothole, it's tire would bounce in, then out, then slam down next to it, creating a new imprint in the formerly smooth stretch of road. Over time, rain and repetition would increase the size of the existing potholes, as this repetition turned the two into three, the three into four, and so on.
Eventually the powers that be would pave over the road, allowing for a smooth ride for a while, until another pothole appeared, repeating the cycle.
In my body it looks more like this: I tried the splits once and pushed myself too hard, so my groins hurt, and I decided that trying the splits equaled pain. The next time I tried splits I had fear of repeating that pain, which had me tighten my groins. The exact muscles I tightened to protect myself from pain simultaneously made the splits both impossible and painful, reinforcing my association of splits with pain, and further distancing myself from the asana. The first experience caused the second, the second the third, and so on.
I broke out of this pattern briefly, one particularly optimistic day, where I removed the blame off my anatomy and put the responsibility on myself. I aligned my thigh bones properly in their joints, was unafraid, and down I went - all the way down, totally comfortable, and raised my arms happily into the air as I never had before. Letting go of my past experience, and totally focusing on the present released the karma-samskara cycle, and I was free.
Encouraged by that, I tried it again, attached to that last success, pushed myself rather than released myself, and felt sore in my groin the next day, and a new string of potholes was formed. Today, when I am fully present, I get down with no pain and no lingering discomfort, and when I am afraid or aggressive, I don't. It's that simple. The fear runs deep and it takes a lot to release that samskara.
GUILT, RESENTMENT & FORGIVENESS
Guilt commonly acts as a vehicle for carrying forward our own unresolved past actions.
Guilt is interest on a debt you never really owed.
Resentment acts as the vehicle for carrying other peoples past actions.
Resentment is like giving free rent to other people in your mind, body and spirit.
Forgiveness is the cure-all for both guilt AND resentment. Forgiveness is "for giving". Please give freely.
THANK PEOPLE FOR HURTING YOU
In fact, any time you feel hurt by something someone says or does, if you realize that they are helping you find and have an opportunity to resolve a past hurt, you also have the opportunity to help them resolve some of their guilty conscience, and can thank them rather than blame them!
Blaming them for upsetting you is like the Department of Public Works blaming you for reporting a pothole.
THE FOUR KARMA-SAMSKARA PATTERNS
The basic four patterns are:
Note that belief is reincarnation is UNNECESSARY for this model. Cultures can carry guilt for actions of previous generations. Germans often carry guilt...
PUTTING IT TO ACTION IN YOUR PRACTICE
Go into your practice with an attitude of curiosity: what will you find? When your body grips up and stops you, blocking your freedom, THANK IT for protecting you from injuring yourself. It has just averted an injury. Generally the tensions we find are to keep our bones aligned.
Breathe where you are. Draw on all those great alignment instructions you've been offered over the years, and even experiment with new ones. Feel into a way of placing your bones that simultaneously prevents the injury, without blocking your freedom.