Geshe-la has been talking about the positive attitude of diligence (joyful effort or enthusiastic perseverence), which is about really enjoying engaging with constructive, skilful, positive actions.
The Lamrim teachings tell us about 3 types of joyous effort
1. Armor-like diligence
2. Enthusiastic perseverence of acting constructively
3. Joyous effort of working for the benefit of others
With enthusiasm we can become Enlightened in the short term. We need enthusiasm to overcome our negative states of mind and develop positive qualities. We need enthusiasm to overcome the self-centred attitude, the constant focus on 'me, me, me' which results in over-exaggerating our problems and leads to depression. If we didn't obsess so much about ourselves and instead cared for others we would never feel down or depressed.
Traditional teachings tell us about Bodhisattvas - beings who dedicate their lives to attain enlightenment for the benefit of all beings - whose enthusiasm and perseverence is developed to the point they'd be willing to be on fire for eons for the sake of one single person!
Winter is a good time to practice Dharma, to meditate, relax, calm down and then face our 'problems', by looking at them and asking ourselves what are its causes; by removing the causes we can change.
Just thinking about our full potential as human beings and all the possible positive qualities we can develop will change our state of mind, as it will bring forth the positive desire and enthusiasm to work towards becoming all that we can be and thus the end of all our problems.
Our main obstacle is laziness. Although we are aware of our potential and how to attain it we delay, we postpone our practice. Or we might doubt our potential or believe we can't achieve it. Maybe we think we have plenty of time to get on with it.
Thinking we have plenty of time, we end up wasting the precious little time we have left following whichever desires arise in our minds - usually chasing up things which, although they may bring us fleeting pleasurable sensations, don't really bring us any lasting happiness.
Thinking about death is a good remedy for this. We are going to die. We are going to die. We are going to die. Sooner or later, we are going to die. Has it sink in yet? Death is not something which happens only to other people. Believe it or not, you are going to die too. And at that moment your possessions won't be of any help. All that you've worked so hard to accummulate won't be of any help. You'll die utterly alone even if surrounded by your loved ones. Nobody will be able to take away your fear and pain of death. When this reality begins to sink in we begin to realise how precious our human life truly is. We have wonderful conditions. Right now there's so much we can do. Now is all we've got. Now is the time to create happiness and all happiness is produced by practicing Dharma. 'Practicing Dharma' may sound alien and weird - all it means is letting go of all that brings suffering and develop all that brings happiness.
What stops us from doing this? Sometimes we are overwhelmed by self-contempt, by thinking "I just can't do this! How can I let go of anger, resentment, jealousy, depression, fear, anxiety, etc etc? There are so many negative emotions! It's really hard to stop desire, hard enough not to eat an extra slice of chocolate cake, hard enough to stop smoking, let alone give up all negative emotions! It's hard enough to learn a foreign language let alone attain omniscience... This practice is impossible! Maybe some people have stomach for this but this is definitely not something that I, me, myself can do, no way!" Discouragement and lack of self-belief is a major block. We need to develop great enthusiasm.
We are told that even flees can achieve Enlightenment, that we all have Buddha Nature - please don't be put off by words, all it means is we all have the potential for unlimited unbiased love and knowledge or wisdom. Buddha was a person, not a Creator God, and he represents our potential. We are offered a vision of what we can become and sometimes it is hard to be open to possibility.
We've been conditioned to believe that we are small, insignificant, powerless, even bad or evil. And yet we are not bad, and these ideas are totally wrong. We are amazing beings who constantly limit our potential by wasting time with such nonsense as getting afraid we won't have enough money.
If you feel sad that so far you've wasted so much time, if you're going through a hard time telling yourself off for not having done more to develop your potential then that's a good sign because it means you are trying. You moved on from being someone sitting on the couch in front of the TV watching a football game, believing that playing football is an easy thing to do and critizising the players to someone who's going in the match to play and is realising how hard it actually is. So rejoice and be happy!