Learning Torah for its own sake [not for money] constantly and with energy (with תמידות and מרץ) is an issue that comes up in Litvak yeshivas. Some people have found that making a yeshiva is a good way to make money, so they pretend that this goal of learning constantly and with energy is, in fact, their goal. Others are straightforward enemies of this goal. They hate the idea of people learning Torah for its own sake. But if it is for money [like they do] -then it is OK.
This is not just an issue of a some intellectual puzzle, but for me was and still is a very personal issue.
The reason kollels were created [the original idea started with Reb Israel Salanter] was to remove one of the biggest obstacles of learning Torah--marriage.
That to some degree might seem to help, but to me it looks like it just contributes to the problems of people using Torah to make money.
The best idea to marry a "Bat Talmid Chacham" (the daughter of a authentic Torah scholar) [not the phony types].
The general answer to this problem is not known to me, except that people ought to be taught the importance of learning Torah for its own sake, and to do so on one's own, and to support the Litvak yeshivas which in fact do this.
I had a long history in this subject. To go into it in detail seems too much for me right now. but in short the issue can be divided into several time periods.
Time Period I: Yeshiva. That is where I first encountered the concept. Later reading the Nefesh Hachaim made it more clear. [The issue was not really dealt with in more general books of Musar]
Time Period II. Getting married. The girl I married was not exactly a Bat Talmid Chacham (the daughter of a authentic Torah scholar), but she certainly appreciated what I was doing in yeshiva.[Her father was a working guy.] Something about what I was doing seemed to affect her in some kind of deep way--enough to get her to run to NY and chase me for years, in spite of my constant refusals [and rude refusals.]. I guess you would have to say that something of the spirit of Authentic Torah must have touched her soul.
Time period III. Getting involved in Breslov. In some ways great. But as far as learning Torah goes, it caused me to lose interest. It is given lip service, but the actual essence is gone. Still that was a great period in many ways. It gave me interest in getting to Israel, and for the seven years I was there there was a kind of opening into a higher consciousness.
Time Period IV. I found out how nasty the religious world really is. A tremendous effort was spent after I returned to California to separate me from my wife and children all because I was learning Torah. That is learning the hard way to stay away from the religious world and the demonic "Torah teachers" that are obviously into Torah because that is where the money and power is.
Time Period V: trying to figure it all out. One good approach I discovered is Schopenhauer. He does deal with this question in a straightforward way. Human good is not something that interests the "Will."
That is however not very satisfying in my own case since it seems clear that in any case for the seven years in Safed I was not doing much learning Torah anyway. So it is kind of expected that when one has gone away from learning, and then tries to get back to it, that obstacles will be encountered.
In any case, I am no poster child for this particular position. If I got back into learning at all, it is a due to David Bronson with whom I learned Gemara with after all the above mentioned events.