A Bird in Hand is Worth Two in the Bush

One has to be satisfied with what one has got.  It is risky to aspire too high.  There are instances of men who prompted by over-ambition and greed have launched big schemes and ruined themselves.  To be ambitious is, of course, good.  No great achievement is possible without ambition.  But to be over-ambitious is bad.  So don't aspire for too many things and lose what you already have.  It is better to consolidate what you have than to embark on hazardous plans.  A small certain gain is of greater value than a larger, speculative one.  Don't trade certainty for uncertainty.  This is what is meant by the proverb 'A bird in the hand is worth two in the bush.'