In real life, most people don't meet their own expectations, or society's expectations, for that matter.

Just some suggestions to make the sentence sound a little more conversational / fluid.

In my opinion, most people think they cannot do anything after they see successful peoplgive up on themselves when they see some of the things that successful people manage to achieve.

What you wrote isn't wrong at all, but here's an alternative way of phrasing it.

So mMany people won't even try the slightest bit, but some resilient people will try until they succeed.

Then hHow do we succeed in life, then?

It would be more natural to order it this way