I trust it better than using pet names or other words as passwords. I don't trust anything on the internet completely (for example I don't use ATMs nor online banking).
Where you run into problems with passwords is using the same password on multiple sites. People generally don't "crack" people's individual passwords, they hack a site where people have login accounts and get the list of usernames with their passwords and then use that list to try to log into multiple other sites and when they get a hit they start taking over your accounts. Keeping different passwords for every site you log into is the cornerstone of online security (making the passwords hard to guess just adds another layer of security).