Thanks to compounding, even modest investments done over a period of time accumulate into a significant sum. This is why starting investments early, without waiting to accumulate a big pile of cash, is important. Also, some investments should be ring-fenced for important goals, not be used for anything else however urgent-retirement corpus, for instance, cannot be used to fund children's education, buy a car or go on a vacation.
That said, investments should be made only after preparing a blueprint first. The blueprint has to be thought out well, accommodating all important goals in one's life. If done right, it would help people fulfil their dreams without much difficulty.