Dosh is the answer in almost all cases I suspect, second to not having a mentor or buddy who can give inspiration.
I was so fortunate when I was immediatly post PPL in having a local flying school owner who was keen with a capital K to expand people's horizons. Not only would he hire you an a/c (got to make a living) but he would suggest things and come with you to show you the ropes, always pushing you that little bit further. Much more value than any discounted rates or cheap hours. Buddy up with someone with a passion.
I have been into my local flying club on a Saturday and looked for someone to sit in the RHS for a trip to France or Germany or wherever and no one wants to go. They are institutionalised into going nowhere. Equally, when I have been stuck somewhere in my dial free aircraft due to weather, I have phoned the club and said, find someone to fly the airway equipped a/c to the ILS equipped airfiedl I am stuck at the fetch me, and no one wants to know. PPL training schools are the aviation equivelant of your granny driving her fiesta to Tescos and back.
On the dosh front, if it were no object and you could take a three week break to go to Malaga or Cassablanca who would not do it. Counting the pennies and aviation are mutually exclusive, sorry, wrong hobby.