Safe

When I started to play one of the first things I learned is the towers are safe. If you reach your tower the nasty enemy heroes will cease chase and let you live to fight another day.

Until the day a lvl 7 Nightstalker just dove my tower and killed me before the tower did him much damage.

It was a good experience because it broke my concepts of how the game worked and made think out of the box. If Nighstalker  can kill me under the tower so early in the game, maybe there are more stuff I can learn to tip the balance.

DOTA is the kind of game you always learning some new strat and outsmarting the enemy is halfway to win the match.

The other half is to pick Drow. :P