I am currently leaning toward this: "IF YOU DON’T HAVE A GOOD REASON TO BE BEARISH, YOU SHOULD BE BULLISH."

My thoughts exactly. SPY is currently trading above both its 200-day and 50-day moving averages. I'm retired. I'll reduce my exposure to the market if it falls below the 30-week or 40-week moving average.

I'd hate to get 4%-5% when stocks get 25%, but would hate it even more to get -15% in stocks and lose a big part of that huge gain.

You need some exposure to the market to combat inflation, which is a killer that will erode your purchasing power over the coming years. A 60:40 portfolio is designed to do that. The 60:40 has been analyzed to death and Monte-Carlo-simulated to death by retirement advisors. The 60% ratio that is in an index ETF can be lowered as the years progress within your retirement lifespan. To be safe, you should assume that a withdrawal rate of 3.5% to 4% of your total liquid assets plus social security will meet your annual living expenses.