Taking ownership over something (say a project) means you take FULL responsibility for ensuring that what needs to be done to accomplish the project, gets done. It also means you take responsibility over the result of the project, so if it succeeds, you take credit, but if it fails, you take the blame (even for reasons that, initially, appear out of your control).
This concept became very apparent to me when I wanted to get lean but I was with a partner that loved eating sweets and junk food. Whenever we were together, she’d be eating junk food, whilst I ate my steamed chicken. Of course I was tempted by her food, and whilst it was frustrating trying to be lean in her presence, what I ultimately realised was, getting lean was ALL ON ME. It really didn’t matter what she ate because if I wanted to be lean, badly enough, I would simply not be influenced by her junk food. If I couldn’t resist it in her presence, I would find another solution to ensure I continued eating lean. This had nothing to do with her and everything to do with me. My success (or failure) was entirely MY FAULT.
As an example, if I couldn’t resist the influence of her junk food, I could go into another room whilst she ate. If this still didn’t work, then I could avoid seeing her on the days she ate junk food. If all of this was still not enough (or simply not practical), then ultimately, if being lean was a very high priority, I would break up.
I am not saying any of these measures are what people should do (or are reasonable). I am purely pointing out that if you want something bad enough, you will always find a solution. When there's a will, there's a way.
Often, we delude ourselves and find excuses to not workout or eat lean. This is not taking ownership over the situation. No matter how real the hurdle may seem, we are always capable of rising above it. If you can’t rise above it, then accept that you just don’t want it enough, and that’s ok, but you need to actually realise this.