Mark Twain is absolutely one of my favorites for quotes. His insights are always so penetrating and so penetratingly worded. Here's one:
"Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great."
Positive psychology research has pretty clearly established that a primary indicator and component of "the good life" is the pursuit of personally meaningful, values-aligned, intrinsic goals. For example, Susan Segerstrom in Breaking Murphy's Law , says, "The first rule of doing optimism is pursuing goals." (p. 188.) This just makes sense. It is clearly better to get up in the morning with a feeling and a plan for moving toward something you value.
For someone who is really feeling down and not experiencing much happiness, the first goal may simply be to become happier. This is very doable. We can become happier by learning the skills of resilience, increasing one's positivity ratio, learning and using our strengths, and creating more, better, and stronger relationships. Positive psychology has mapped out complementary approaches that work across these areas.
Once things get better, however, it is likely we are going to feel pulled toward a future that aligns with our values. Most will formulate a purpose that connects with something bigger or greater. And, it's at that moment that Mark Twain's comment comes into play. At that point, it is important to find people who support us in our efforts, and to ask for the support of the important persons in our lives. In turn, perhaps we need to consider whether we routinely help people become great, or hold them back from their ambitions.