Five times leverage means five dollars of exposure for each dollar of your own. A two per cent gain in the asset becomes ten per cent on your capital, and a two per cent loss becomes ten per cent the other way.
The asymmetry is what does the damage. A fifty per cent loss requires a hundred per cent gain to recover, so leverage that amplifies drawdowns makes recovery disproportionately harder even when the original view was right.
It also removes the option to wait. An unleveraged position can be held through a drawdown indefinitely; a leveraged one is closed for you when the collateral runs out, frequently at the low, which is why leverage converts a temporary mistake into a permanent loss.