How does one get this consistency thing done?

Spiritual teachers, parents and every person who is thought to be wise or just appears to be so because of the screwed up face that they have most of the time say that discipline is important. One must do a thing everyday to get better at it, and sure enough it seems very important to get results. I mean if you want to lose weight and get fit, you must exercise every day or atleast thrice a week.  You cannot just decide to start eating healthy and do that just for a day or two and expect results. Even to perfect an art one must do it regularly.

Then why is our generation, or atleast most young adults in the age of 20-25 finding it difficult? We don’t want to do the same thing every day. We cannot get our selves to exercise, we want to try new cuisines every day. We don’t want to sleep at the same time every night. We are constantly searching for stimulation and for our lives to be bigger and larger than it already is. We fear having a monotonous life and that is why we cannot have consistency like the previous generations did, and sure as hell, we will be nagged about it till decide that we are going to sort our lives, only to wake up the next day seeking a more happenning life!