Growth in life - physically, mentally, emotionally, financially and otherwise comes through diligent training and repetitive effort.
In weight lifting, this type of growth comes from something referred to as "progressive overload."
Whenever I'm training in the gym, I'm quick to remind myself to do 1 more rep, to lift 5 lbs heavier, to do an extra set or exercise because progressively overloading my body with more stress is what causes my muscles to grow.
Our minds are no different. If we wish to get smarter and better intellectually, then we must progressively overload our minds as well.
Reading every day, writing every day and intellectual challenges are 3 of my favorite ways to grow my mind.
Reading - I read every morning. I have a library of books downloaded to my phone and ipad, so there is no excuse for me to not read. I always have something available to read at my fingertips.
I read for a minimum of 30 minutes a day, but typically I read for more than an hour. I go based on how I feel and how much work I have to do that day. But I never fail to hit my 30 minute minimum and I always try to "overload progressively" by adding in more time here and there.
For example, sometimes I have extended reading sessions (several hours) for 1-2 days each week. This simply propels my progress and allows me to get a lot of extra "mental exercise" in.
Writing - I write everyday, regardless of what's going on. I have evernote on my laptop, iPad and iPhone, so I have no excuse to not write - similar to the reading.
I've found writing my feelings and deep thoughts about different subjects to be extremely eye-opening and beneficial to my mind. I feel like a mental cloud was fogging up my brain until I started writing. Now that I write so much, my mind feels as though new room has been cleared up for new thoughts.
Intellectual Challenges - you could think of these challenges as being sort of puzzles or problems to solve.
I'm always on the lookout for problems to solve and I love solving them. Whether it's a simple technical problem for a family member or a complex idea that I'm trying to breakdown or a new investment strategy that needs to be put into a spreadsheet to be better understood.
Solving problems will make your mind so much stronger. It strengthens every part of your brain. In my opinion, our bodies and minds evolved to solve problems. Thousands of years ago, our ancestors had to fight to survive and find food and they had to constantly problem solve.
Today, life is so much easier and if we're not careful, we can aimlessly meander through our days with no problems to solve and thus, no growth to be had.