Ask HN: Successful entrepreneurs, what (non-startup) areas in life did you fail?

My mentor once told me, "you can have it all, just not all at the same time."

Time and time again I forget and try to do it all, and I end up frustrating myself. I know this, but I often forget: If I want to succeed at the things that are important to me in my life (such as building a successful startup), there will be areas in my life that I will have to be ok with getting a failing grade in. (e.g. relationships will suffer, etc.)

It's one thing to try and fail (negative "ROI"), it's another to knowingly accept and say, "ok, I'm going to get a C- in certain areas so I'm not going to invest too much of my finite resources in this area (non-negative ROI)."

Would successful entrepreneurs share with us here what they had to give up?

Personally, I find it hard to keep up with my relationships. If I know that others went through the same, it would make me feel a lot better that it's not just me. (Or if it is possible to have it all, please do tell!)