Becoming a mathematician includes:

• using phrases such as “it’s trivial, really” in real life. 
• trying to convince yourself that the back of the book is wrong.
• scribbling random math symbols on every piece of paper in your room.
• these said random scribbling are  never in the same direction on the paper. 
• trying to disprove things that have already been proven.
• more often than not considering yourself higher than applied scientists. 

But most importantly.. 
• not being able to calculate the tip at a restaurant.