Do you load your customer’s data on your laptop? Are you able to tell your customer that you are protecting the confidentiality of their data such that if the laptop were ever lost or stolen, the data would not be accessible?
Consider the seriousness of data breaches. Lawsuits, loss of reputation, loss of business and revenue say nothing of loss of employment.
A product like True Crypt (www.truecrypt.org) can encrypt the contents of entire system. However you must follow the recommended practice of a 20 to 64 character password. That means no dictionary words or dates. This practice, renders it exceedingly unlikely to be brute forced.
Follow the practice of choosing a combination of lower and upper letters, numbers, and symbols. Getting good at remembering long passwords is part of the job these days. It is a mark of your professionalism and dedication to your craft.