Domine, labia mea aperiēs, etc., etc.

Fortune sometimes seems precisely to lie in ambush for the last day of a man's life in order to display her power to topple in a moment what she had built up over the length of years, and to make us follow Laberius and exclaim: 'Nimirum hac die una plus vixi, mihi quam vivendum fuit.'  [I have lived this day one day longer than I ought to have lived. -- Macrobius, Saturnalia]

The good counsel of Solon could be taken that way.  But he was a philosopher: for such, the favours and ill graces of Fortune do not rank as happiness or unhappiness and for them great honours and powers are non-essential properties, counted virtually as things indifferent.  So it seems likely to me that he was looking beyond that, intending to tell us that happiness in life (depending as it does on the tranquillity and contentment of a spirit well-born and on the resolution and assurance of an ordered soul) may never be attributed to any man until we have seen him act out the last scene in his play, which is indubitably the hardest (Erasmus, Apophthegmata, V).  In all the rest he can wear an actor's mask: those fine philosophical arguments may be only a pose, or whatever else befalls us may not assay us to the quick, allowing us to keep our countenance serene.  But in that last scene played between death and ourself there is no more feigning; we must speak straightforward French; we must show whatever is good and clean in the bottom of the pot:

Nam verae voces tum demum pectore ab imo
Ejiciuntur, et eripitur persona, manet res

[Only then are true words uttered from deep in our breast. 
The mask is ripped off: reality remains. -- Lucretius]

That is why all the other actions in our life must be tried on the touchstone of this final deed.  It is the Master-day, the day which judges all the others; it is (says one of the Ancients [Seneca]) the day which must judge all my years now past.  The assay of the fruits of my studies is postponed unto death.  Then we shall see if my arguments come from my lips or my heart. -- Montaigne, Essays, 1:19

Must no one at all, then, be called happy while he lives; must we, as Solon says, see the end? Even if we are to lay down this doctrine, is it also the case that a man is happy when he is dead? Or is not this quite absurd, especially for us who say that happiness is an activity? But if we do not call the dead man happy, and if Solon does not mean this, but that one can then safely call a man blessed as being at last beyond evils and misfortunes, this also affords matter for discussion; for both evil and good are thought to exist for a dead man, as much as for one who is alive but not aware of them; e.g. honours and dishonours and the good or bad fortunes of children and in general of descendants....

Now many events happen by chance, and events differing in importance; small pieces of good fortune or of its opposite clearly do not weigh down the scales of life one way or the other, but a multitude of great events if they turn out well will make life happier (for not only are they themselves such as to add beauty to life, but the way a man deals with them may be noble and good), while if they turn out ill they crush and maim happiness; for they both bring pain with them and hinder many activities. Yet even in these nobility shines through, when a man bears with resignation many great misfortunes, not through insensibility to pain but through nobility and greatness of soul. -- Nichomachean Ethics, Book 1:10