Jim Cramer explains that the start of the year is emotional, with momentum buyers, tax-loss rebound buyers, and buyers of mistakenly sold stocks creating a strong tape. He highlights the AI-driven data explosion as a major catalyst for storage stocks like Western Digital, SanDisk, Seagate, and Micron, noting short covering is amplifying the move. He also points to a shortage of machines that make memory chips, which is lifting semiconductor capital equipment makers Lam Research, Applied Materials, and KLA. Cramer warns that such emotional buying can become irrational.