Acne is caused by certain foods The common misconception is that eating junk food will lead to or worsen an acne condition. Scientific studies have shown that diet has little to no effect on acne. This varies depending on the person. While eating healthy and balanced diet is encouraged for our health, there is really no scientific evidence that connects certain foods to acne. If you are one of those who are affected by certain foods, it is always wise to avoid them.

Stress can cause acne Stress cannot directly cause Acne, but it can influence recurrences of Acne because it increases the body's production of a substance called cortisol
Cortisol causes your sebaceous glands to increase production, which can block pores. Stressing the body (by losing sleep, drinking coffee, skipping meals, ect.)  also increase the productions of adrenalin, which slows down the natural shedding of the skin's  outer layer. dead skin cells build up and clog pores, increasing susceptibility to Acne.

Acne is not a caused by a poor hygiene. Many people believe that acne is caused by poor hygiene; therefore they tend to over-wash their skin. However, washing too frequently and too aggressively can strip the skin of its natural lipids, damaging the skin's natural barrier function. In response, the follicle will produce excess sebum and possibly additional breakouts. So unless you get yourself dirty on regular basis (like a mechanic, perhaps), do not over-wash your face.

Acne is just a little problem, no need to overreact. It is embarrassing to have acne, thus can affect our confidence and esteem. It may even affect our social relation and job performance.

You can outgrow your acne. It is much more sensible to treat your acne immediately to avoid emotional stress and permanent scarring.

Acne is just a cosmetic disease. Heavy and oily make up may contribute to acne build up. However, cosmetics labeled non-comedogenic or non-acnegenic might actually contain benzoyl peroxide and salicylic acid that may help to fight acne.

Getting a tan would clear up acne. While sun exposure may dry out existing acne, it will not prevent new ones from forming. It can also over dry the skin thus sebaceous glands will produce more oil that will ultimately worsen your condition. It will also increase your risk of skin cancer and wrinkles.

So there, the next time somebody tells you one of those things, gracefully correct them and share what you know. Remember, knowledge is power.