Three big mistakes, taught me long term perspective.
1) Bought Infosys in 1995-96, sold with some profit in 1996. It is 1500X.
2) Bought Shree Cement in 2000, sold after two years with no profits. It is 600X.
3) Bought Aarti ind. in 2008, sold in 2013 with 2-3X. It is 80X.