In order to understand customer behavior along the journey, you’ll need quantitative and qualitative data.
Quantitative data, based on numbers and metrics, can be found in your marketing and CRM software (think sales figures, website visits, email clicks, social media engagement statistics).
Qualitative data is about describing experiences and is obtained through observation and investigation, such as interviews, surveys, customer support tickets, and so forth. Intuition is a good place to start when coming up with new strategies, but using data to support those hunches is the best way to optimize the user experience and improve marketing strategy.