"Once you can accept the Universe as matter expanding into nothing, wearing stripes with plaid comes easy" Albert Einstein
When we perceive life as happening to us and viewing our experiences as extrinsic to our internal processes, we are challenged to accept life. Acceptance is not about giving up or accepting "your place". It's about accepting that you are where you are and that you have a choice about where you are going. However, that choice might instead be about your attitude to your current situation. Acceptance is being ok what is and what has been, but striving for optimising one's own experiences.
Acceptance is a state of flow and grace. You embody a permission state that allows you accept the opportunities in life, whether they are to teach you a, at the time, harsh lesson or something fully in alignment with your path towards the optimal version of yourself. The universe is beautifully complex, and there is no way for our conscious minds to fathom it all. When we try to figure it out and force our will through we exert control, which works in opposition to acceptance. Imagine the river stopping because of some logs and rocks saying, " I am not flowing any further until I break through these obstacles". It doesn't do that, it flows with those obstacles accepting them as part of the river. When we are sleep walking through life we tend to involve ourselves in the paths of others either to rescue them or because they are doing something "to" us. The paths of others are outside the boundaries of our control and the best we can do is to accept the choice of others and know we can only control our thoughts, words and actions, and accept our responsibility for them.
This is a "permission" state of mind where you allow yourself to flow through life, with all its ups and downs, knowing that you have your grand purpose and all your experiences bring your closer to it. When we accept we are in a receiving state as opposed to when we try to control everything or trying to retrieve our dues.
When we shift focus inwards and understand what is in our purview of control, what is our path, purpose and mission, understand our own super powers, understanding where we come from and allowing ourselves to feel; we will start to accept. When we understand our position in cosmos, we accept our role as the drop in the sea, without every one of us it would not be a sea.
Acceptance is a paradox; when you accept life for what it is and bring in how you want to feel in life, there will be less for you to simply accept and more to enjoy.