No I own all my errors and mistakes, it's a sign of weakness to always make excuses about why it's not your fault and how you're never wrong, plus you look a total tool.
There's a distinct difference between apologising and owning up to ones mistakes and doing ones best to make amends. The origin of the meaning of apology was to attempt to present a defense for one's actions.
I could spend the rest of my life apologising for my each an every imperfection however large or small had I intentionally led anyone to unrealistic expectations.
There's also a distinct difference between understanding how and why we did something wrong and failure to assume full responsibility for one's own wrong doings, regardless of intentions.
My motto has always been, "Don't be sorry . . . be right!" But if I've led anyone other than me to believe that I insist they follow this creed themselves as well . . . I apologise. OK, so I have double standards. So sue me!
// It's rare I do anything I 'should' apologise for. //
That's only your opinion of course. Everyone around you might disagree and think you often do things you should apologise for.
Personally I always apologise when I think I need to, which is fairly regularly.