Irving Fisher, another great economist, wrote in 1930:
The uncertainty of life itself casts a shadow on every business transaction into which time enters. The Theory of Interest, Ch. IX, p. 216.
So it's not so much that it takes time to reach the future; it's that the future is unknown.
And tastes are convex. That is, we would like to smooth consumption over time (as well as across goods). Thus we want to plan for the future, but uncertainty makes that hard.