Logically speaking, there is no "must" or "must not" when there is no goal to depend upon. A goal is something that we choose to pursue and eventually achieve. Therefore, as long as you do not have an ambition that you wish to achieve, there are no things that you must do in order to actualize a non-existent ambition. For there must be a goal in every pursuit.
It is always dependent upon a purpose, whose components and actions are required in order for that purpose to be achieved.
For example, I do not really need to shave. However, because my ambition is to keep the aesthetics of my face and prevent my face from being itchy, I must shave in order to achieve that ambition. Without purpose or any other functionality, there are no necessary components that you must fulfill.
Social pressure is a very annoying aspect of our lives. Just because you are under pressure by other people, it does not mean that you must follow as they do, no matter how convincing they are. Social pressure alone is not enough of a purpose to succumb to others, regardless of their affiliation to you. Once you are a free citizen, your life, ideally, is yours to do with as you please.
Since your life belongs to you, it is primarily up to you to decide what purposes you wish to actualize. Thus, if you wish for a simple life, it is your undoubted right to live a life of simplicity; if you wish to be great, the same conclusion follows. Being told what to do, and doing so for its own sake, is but the property of a true prisoner, official or not.
When it comes to lifestyle, there is no "enough" or "not enough" in endeavor, beyond what we choose to tell ourselves or to believe. You don't have to be simple, nor great. There is no law from the state that demands you to be either of those opposite values. It is generally, if not solely, your choice to be either of them, or even mediocre if you desire, regardless of reception. This is much more true if you are an adult.
Personally, I combine those values in my lifestyle. I live a relatively ascetic and hermetic life. When there is no work on a specific day, I barely talk to anyone, and I very rarely get socially involved beyond the interaction between me and my family.
However, I have decided to live such a simple and serene life to make room for philosophical contemplation and writing philosophy. I call this lifestyle Philosophical Asceticism. I present you my personal example in order to show you that you can both live simply and peacefully, and to achieve greatness at the same time. They don't have to contradict themselves, for they can even be united into a hybrid.
If you attempt to follow the path of greatness, take note that you cannot control the memory of others, let alone after your death. The possibility of you being remembered for an extended period of time is dependent primarily, if not solely, on others.
Many people who have made many inventions, theories, and works of art are remembered because their creations have surpassed them in the collective memory. I myself am not even sure who invented the television, Wi-Fi, or corn flakes, despite their value.
If you desire to be remembered as a great person, not because of social pressure but because of your own desire, try to create and compose great things, and the possibility of you being remembered long after your death will increase. However, do not rely too much on this hope, for life is not fair for theoretically everyone in this world.
