Ambition is the last refuge of the failure.

Plans for what you will be can function as shelter from what you are. Ambition is respectable, unfalsifiable while it stays in the future, and can absorb decades of a life without ever being tested, which makes it an ideal place to hide from a present that is not going well. The barb here is aimed at that use of it, not at wanting things.

Worth checking which you have. Ambition that is being acted on this month produces evidence, however small. Ambition that only ever produces descriptions of a future is doing something else for you, and it may be worth asking what.