Sometimes you get bored to death with too much of free time
No big surprise that you will forget your basics and doing crap work for sure
After few years, you may be considered a candidate fit for nothing elsewhere than IBM
People Managers are the one who rate your performance and decide your career advancement and the dying truth is that they are not part of your project and never can get the factuals about your contributions.
Do not kill yourself when you get a hike letter for 0.1% even after your outstanding performance
After all freedom that you enjoyed in IBM, you will be shocked to realize that you lost the right to leave the company, you will be literally jailed to serve 3 months notice mandatorily.