On a larger scale, to me, success is being able to live comfortably doing what I love to do, having more good days than bad, living with my love in a cosy place we call home and experiencing the world - different cultures, different thoughts, different opinions. Success to me is saying yes to all things I wish to do in spite of my fear and anxiety.
Life is hard when you fixate on the smallest of things - over thinking and talking yourself out of experiences you know you will enjoy, because what about all these things that could go wrong?! It's funny how the person who wants you to progress and achieve great things is the same person who stops you in your tracks with "what if's" and "no, that's out of your comfort zone, you're not doing that!" - it's even funnier that it's yourself doing those things. Overcoming those thoughts, even just for one day, one experience, is a success in my eyes.
Success is not a checklist, nor is it achievements that are engraved in stone. You make your own definition of success. Whether it's owning a house, having a family, becoming the manager in your job, passing an exam, learning an instrument or becoming fluent in another language. Success is perception, and everyone's is different.