[quote=@KnightShade]
You don't [i]become[/i] an adult, you just get better at pretending you've got your shit together.
[/quote]

No you don't, you just have more time to collect more stuff so you look like more of an adult. 

Also, 20 is thereabout that age where everything suddenly speeds up. The gap between 18 and 20 feels about as long as the gap between 20 and 25.