Texas - buying and selling real estate

I was researching the laws in Texas concerning buying and selling properties and came across this PDF on obtaining a real estate license. I decided to see what it involved to get one and the steps required. What bothered me was the following text ( please remember I am very new to RE).

What activities require an active
Texas real estate license?
An active license is required for
anyone who performs specific real
estate activities on another's behalf for
an actual or expected fee, commission
or other remuneration. These activities
include:
• selling, exchanging, purchasing
or leasing real estate;
• offering to sell, exchange, purchase
or lease real estate;
• negotiating or attempting to
negotiate the listing, sale, exchange,
purchase or leasing of
real estate;
• listing, offering, attempting or
agreeing to list real estate for
sale, lease or exchange;
• appraising, offering, attempting
or agreeing to appraise real
estate;
• auctioning, offering, attempting
or agreeing to auction real estate;
• buying, selling or offering to buy
or sell or otherwise dealing in
options on real estate;
• aiding, attempting or offering to
aid in locating or obtaining real
estate for purchase or lease;
• procuring or assisting in procuring
properties for the purpose of
selling, exchanging or leasing
real estate; or
• selling, buying, leasing or
transfering an easement or rightof-
way for use in connection
with telecommunication, utility,
railroad or pipeline services.
Right-of-way agents (see last listed
activity) must have an active real estate
license or be registered with the commission
to practice their profession.
In addition to listed activities, the act
requires any person employed to sell
all or a part of a parcel of land for the
owner at a salary, fee, commission or
other valuable consideration to have
an active real estate license.
Also, an active real estate license is
required of anyone who charges an
advance fee or collects a fee under a
contract to promote the sale of real
estate. The promotion may be through
a real estate publication or a referral.

In the above it states buying, selling and leasing property to others and receiving a fee. So my question is - How does the investor in Texas do this without having a license? I have talked to several realtors here in town and they all stated the same thing. In Texas you cannot buy, sell, or lease properties and receive a fee you must use a realtor. So I am confused.
Hopefully someone here perhaps is doing this in Texas and can possibly help me.

Thanks,
Tammy

P.S. The PDF can be found here.
http://recenter.tamu.edu/pdf/1149.pdf