Well I'm a liberal and proud of it. If you take a moment to consider the trend of human history, you'll see that we have made a slow but steady move toward liberalism. Conservatism, by its very nature, looks backwards and not forwards.
Liberalism seeks the future.
While liberal and revolutionary movements have sometimes gotten off track or made false starts, the most important turning points in history have been effected by people who would have been considered to be radical in their day. Consider the effects of the New Testament, the Magna Carta and the Declaration of Independence - each is a definitive document which heralded new, liberal world views that are now held as truisms by liberals and conservatives alike. You may also note that many of these brilliant liberals have been vilified, persecuted, imprisoned or even killed by the conservative elements in their respective societies. Because conservatives use fear of change and ridicule of political opponents as their chief political tools. You can, too.