Doing is the best way to learn. You’ll find out very quickly what your strengths and weaknesses are. And it’s the only way to get anything done.
But you’ll keep doing the same things unless you have time for some thinking around the doing. Thinking is crucial in order that you spend your doing time doing the right things, things that can help you grow and learn.
Too much thinking stymies progress however. It can be the enemy of doing. It’s sometimes easier to sit on your own and think rather than endure the public scrutiny that doing can bring.
The trick is to have enough time for each, to know which stage you are meant to be in at any one time, and to give it your all and carry each particular stage out as efficiently as possible while you are there.