An umbrella in a dream usually points to protection -- something you're using to guard yourself against an emotional storm you sense is coming. Forgetting your umbrella in the rain can reflect feeling unprepared for a difficulty, while a sturdy one often names readiness you've quietly built for yourself.
Be wary and circumspect in your judgment, when a fortune is with a malevolent; nor be you overconfident that the malice of the infortune shall be averted. - William Lilly (1602.-1681.)