You feel that you lack the knowledge to do something great, so you will just accept that you are a dumb person and will not study things anymore. Is that really a lack of something? or a lack of will? Is it really true that you are not smart? or you are just a lazy bumass person wanted to be fed without doing something? what is the truth? the lackness or the laziness?
You feel that you lack the height so you can't make it to the pro basketball league. Every time you play basketball you always feel the scarcity of height. That is why you are so afraid to challenge players that are taller than you. You think that they can stop you easily, you feel little for yourself. What if you are brave? what if you look like a crazy person ready to challenge anyone on the court? what do you think will be the result? is it the lack of height or the lack of courage that is stopping you?
You want to go to a party but you feel like not going because you don't have a car, you don't want to commute because it is inconvenient and you don't want your shoes to get dirty. Now the feeling of lack is making you stuck, you want to go but you feel you lack something that is why you can't achieve something.
You always feel that there is something lacking in your life that is why you can't progress. The reality is your life is already complete, you already have what you need. There is always room for improvement, you can upgrade your life but you should accept first that nothing is lacking in your life. Your life is already perfect, your perception is what makes you feel the incompleteness.
Some people feel like the universe owes them something and they need to have it first to feel good and do something great. The truth is nothing is lacking in your life, all you need to do is appreciate what you have, if you are not satisfied then do something about it and don't act like you're a son or daughter of the sultan of Brunei and things should be handed to you before you act.
Stop being a cry baby, stop being a whiner. You're a grown up individual, just move chico!
Some cases are true that you lack something but if you feel that you have a lot and you can find a way how to fill that lackness then you are unstoppable. You can do anything, you can achieve greatness.
Have the ability to adopt. Find ways how fill that void, fill that hole in your soul with positivity and abundance. Be a person who is confident enough even if you really have nothing, even if you are lacking something. Again, it is a matter of perception, what you feel inside will be your reality outside.