> Replacing the transmission in my truck: shop wanted $7k, I did it all for $2.5k > Fixing my deck and expanding it: contractor wanted $55k, I did it for $7k

> Replacing the transmission in my truck: shop wanted $7k, I did it all for $2.5k > Fixing my deck and expanding it: contractor wanted $55k, I did it for $7k > Leaky pipe in ceiling: plumber wanted $1k, I fixed it for $25. How did you learn to do these things? There are many chances where things could go horribly wrong.