To observe and watch one's own mind is something really interesting. The untrained mind will run and follow its old habit patterns. Because it has not been trained and taught, it will get lost in all kinds of stories and issues. Therefore we have to train our mind. The meditation practice in Buddhism is all about training one's own mind.
To define Buddhism without a lot of words and phrases, we can simply say, 'Don't cling or hold on to anything. Harmonize with actuality, with things as they are.'