Different people and cultures believe different things for the answer to this question. The meaning of life as we perceive it is derived from philosophical and religious contemplation of, and scientific inquiries about existence, social ties, consciousness, and happiness.
A long-term financial plan should include these elements. Time Horizon. A plan should look at least  five to ten years into the future. Scope. A plan should consider all appropriated funds, but especially those funds that are used to account for the issues of top concern to elected officials and the community. Frequency.
For this reason, accountants often recommend keeping personal financial information for up to seven years. The IRS will only do this if they believe your figures are off by 25% or more. You should keep pay stubs for a year after the tax year they are part of, along with the W-2. After one year, destroy the stubs but keep the W-2 and tax filings.