Some organizations tell people that some things which clearly aren't sins are. For instance, some organizations tell their adherents that eating red meat on Friday is wrong. Some organizations tell their adherents that not recycling is wrong. Some organizations tell their adherents that fracking is wrong. Some organizations tell their adherents that racial mixing is wrong.
My religious organization teaches that I am to treat my neighbor as I want to be treated. It teaches to forgive others if I expect to be forgiven. Of course, if these tenets are applied, it becomes clear pretty quickly that I shouldn't commit adultery, or be filled with jealousy (jealousy has some pretty nasty ramifications often enough for it to be a destructive thought pattern), or commit murder, or drive drunk, etc.
Generally speaking, I avoid sin because I realize it's destructive nature - to me and to others. Now, like you, that 's not to say I don't "make an oopsie," ie, "sin," - but my moral standard, which my religious beliefs help form (my life and experiences also form, and continue to form, my moral standard) affirms to me that sin is generally very destructive to myself and/or others, so it's a good thing to avoid. Now - do I WORRY about it? Well, worrying isn't really a big part of my natural personality - I'm just not wired to worry, I guess. But I do take precautions when it comes to sin. I installed a security system and I lock my doors at night - because I know that some people sin. I try to eat a healthy diet because I know that the sin of gluttony or the act of disregarding my body's health has destructive ramifications. I married a person of good moral character because I know that some people are more prone to, and some people are less prone to, committing adultery, which is unacceptable to me when it comes to my marriage. And it's unacceptable to me because of it's destructive nature and the hurt it can cause other people - not simply because "God said don't do it." But God DID say "Don't do it," and I can see why.
In other words, my faith is mature and has grown into the understanding of WHY "the ten commandments" are relevant. I don't blindly follow them - I follow them because I believe they are relevant and make good sense. And I'm grateful for an upbringing in which I learned these tenets BEFORE I was able to see just how applicable they are to life.
But I've also been around long enough to realize the limitations of my human understanding and perspective, and that's when my faith steps in and comforts and supports me emotionally and spiritually.