Difficulty signing into a Google account could stem from a few common issues, such as forgotten credentials or unrecognized devices. Initially, attempt the password recovery process provided by Google, which will guide you through steps like verifying your identity and setting a new password. If the issue persists, checking for any possible service disruptions or contacting Google Support might be necessary. Ensuring your browser is up-to-date and clearing cookies and cache can also resolve sign-in issues.