This also just came to me recently in a discussion - The fact that an individual themselves can be their own obstacle in case they overshoot their goals, especially having in mind what they are capable of becoming or doing.
This is probably the biggest obstacle, being realistic about these things.
Yes, there are indeed many obstacles within ourselves. and that is even an actual fact. for example that ourselves can be the biggest obstacle to achieving financial freedom is Lazy (not working optimally, using more free time for fun and playing than looking for opportunities), Excessive fear (not daring to try new things, not dare to go further, always afraid to try before taking a step, don't dare to take a new opportunity, prefer to be in a safe position and don't dare to take challenges), and pessimistic. and there are many other traits and characteristics within us that become obstacles if we can't control them properly.